Dissertations / Theses: 'Microsporea'

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Sato, Vanessa Sayuri [UNESP]. "Produção de fitase por Rhizopus microsporus var. microsporus: purificação, caracterização bioquímica e aplicação." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/124519.

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A investigação biotecnológica acompanhada da aplicação das enzimas, combinada com o uso da engenharia genética tem sido realizada em micro-organismos para a produção de enzimas para fins industriais. Entre estas enzimas, as fitases microbianas, que catalisam a hidrólise do fitato (mio-inositol hexaquisfosfato) a mio-inositol e fosfato inorgânico, têm sido amplamente utilizadas na alimentação animal. Neste contexto, o fungo R. microsporus var. microsporus foi selecionado como bom produtor de fitases, com maiores níveis de produção encontrados na Fermentação por Biofilmes (FB) (261,30 U/mg), utilizando bagaço de cana de açúcar como fonte de carbono adicional. A morfologia do biofilme sobre suporte inerte foi analisada por MEV observando-se múltiplas hifas interligadas formando um conjunto ordenado na presença de inúmeros canais que permitem a troca eficiente de nutrientes e oxigenação. A fitase extracelular obtida foi purificada 4,18 vezes com recuperação de 4,78%, obtendo-se uma única banda de 34 kDa em SDS PAGE 12%. A temperatura ótima de atividade para a enzima purificada foi de 55ºC e o pH ótimo 4,5, sendo estável entre 30 °C e 40 °C por 120 min. Apresentou baixa estabilidade ao pH com atividade residual acima de 50% entre pH 3,0 e 5,0 por 60 min. A fitase foi ativada por íons Ca2+ e inibida por K+. A enzima foi capaz de hidrolisar fitato de sódio (Km de 0,72 mM e Vmax de 94,55 U/mg). O extrato bruto contendo fitase foi seco em Spray Dryer com diferentes adjuvantes (farelo de milho, farelo de soja, fubá, amido e maltodextrina). O farelo de soja possibilitou a maior recuperação da atividade fitásica (60%), assim como o fubá (59,5%). Considerando o uso destes dois adjuvantes, o pH ótimo de atividade para a fitase contida no extrato seco foi 4,5 e 8,5, respectivamente e a temperatura ótima de atividade de 45-50 °C. Quando utilizado fubá, a estabilidade foi mantida...
Biotechnological research, and the application of enzymes in combination with the use of genetic engineering has been carried out in microorganisms for the production of enzymes for industrial purposes. Among these enzymes, microbial phytases, which catalyze the hydrolysis of phytate (myo-inositol hexakisphosphate) to myo-inositol and inorganic phosphate, have been widely used in animal feed. In this context, the fungus R. microsporus var. microsporus was selected as a good producer of the phytase with higher production levels when grown on Biofilm Fermentation (FB) (261,30 U/mg), using sugarcane bagasse as carbon additional source. The morphology of biofilms on inert support was examined by SEM observing interconnected hyphae forming an ordered array in the presence of many channels which enables efficient exchange of nutrients and oxygen. The extracellular phytase was purified 4.18 fold with 4.78% recovery. A single protein band was obtained in 6% PAGE and confirmed by 12% SDS-PAGE as a single protein band with 34 kDa. The optimum temperature for activity was 55 °C and the optimum pH 4.5. It was completely stable at temperatures between 30 °C and 40 °C for 120 min had low pH with a residual activity of over 50% between pH 3.0 and 5.0 for 60 min. The enzyme was activated by Ca2+ and inhibited by Zn2+. The enzyme was able to hydrolyze sodium phytate with a Km=0.72 mM, Vmax= 94.55 U/mg of protein. The crude extract containing phytase was dried using Spray Dryer with different adjuvants. Soybean meal and corn meal allowed the best recovery of phytase activity 60% and 59.5%, respectively. Considering the use of these two adjuvants, the optimum pH of activity for phytase in the dry extract was 4.5 and 8.5, respectively, and the optimum of temperature of 45-50 °C. When used corn meal, the stability was maintained above 90% at pH 2.5-10.0 for 60 min. The dry phytase (corn meal) was applied to the feed...

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Sato, Vanessa Sayuri. "Produção de fitase por Rhizopus microsporus var. microsporus : purificação, caracterização bioquímica e aplicação /." Araraquara, 2015. http://hdl.handle.net/11449/124519.

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Orientador: Luis Henrique Souza Guimarães
Banca: Daniela Alonso Bocchini Martins
Banca: José Roberto Ernandes
Banca: João Cláudio Thoméo
Banca: Patricia Gomes Cardoso
Resumo: A investigação biotecnológica acompanhada da aplicação das enzimas, combinada com o uso da engenharia genética tem sido realizada em micro-organismos para a produção de enzimas para fins industriais. Entre estas enzimas, as fitases microbianas, que catalisam a hidrólise do fitato (mio-inositol hexaquisfosfato) a mio-inositol e fosfato inorgânico, têm sido amplamente utilizadas na alimentação animal. Neste contexto, o fungo R. microsporus var. microsporus foi selecionado como bom produtor de fitases, com maiores níveis de produção encontrados na Fermentação por Biofilmes (FB) (261,30 U/mg), utilizando bagaço de cana de açúcar como fonte de carbono adicional. A morfologia do biofilme sobre suporte inerte foi analisada por MEV observando-se múltiplas hifas interligadas formando um conjunto ordenado na presença de inúmeros canais que permitem a troca eficiente de nutrientes e oxigenação. A fitase extracelular obtida foi purificada 4,18 vezes com recuperação de 4,78%, obtendo-se uma única banda de 34 kDa em SDS PAGE 12%. A temperatura ótima de atividade para a enzima purificada foi de 55ºC e o pH ótimo 4,5, sendo estável entre 30 °C e 40 °C por 120 min. Apresentou baixa estabilidade ao pH com atividade residual acima de 50% entre pH 3,0 e 5,0 por 60 min. A fitase foi ativada por íons Ca2+ e inibida por K+. A enzima foi capaz de hidrolisar fitato de sódio (Km de 0,72 mM e Vmax de 94,55 U/mg). O extrato bruto contendo fitase foi seco em Spray Dryer com diferentes adjuvantes (farelo de milho, farelo de soja, fubá, amido e maltodextrina). O farelo de soja possibilitou a maior recuperação da atividade fitásica (60%), assim como o fubá (59,5%). Considerando o uso destes dois adjuvantes, o pH ótimo de atividade para a fitase contida no extrato seco foi 4,5 e 8,5, respectivamente e a temperatura ótima de atividade de 45-50 °C. Quando utilizado fubá, a estabilidade foi mantida...
Abstract: Biotechnological research, and the application of enzymes in combination with the use of genetic engineering has been carried out in microorganisms for the production of enzymes for industrial purposes. Among these enzymes, microbial phytases, which catalyze the hydrolysis of phytate (myo-inositol hexakisphosphate) to myo-inositol and inorganic phosphate, have been widely used in animal feed. In this context, the fungus R. microsporus var. microsporus was selected as a good producer of the phytase with higher production levels when grown on Biofilm Fermentation (FB) (261,30 U/mg), using sugarcane bagasse as carbon additional source. The morphology of biofilms on inert support was examined by SEM observing interconnected hyphae forming an ordered array in the presence of many channels which enables efficient exchange of nutrients and oxygen. The extracellular phytase was purified 4.18 fold with 4.78% recovery. A single protein band was obtained in 6% PAGE and confirmed by 12% SDS-PAGE as a single protein band with 34 kDa. The optimum temperature for activity was 55 °C and the optimum pH 4.5. It was completely stable at temperatures between 30 °C and 40 °C for 120 min had low pH with a residual activity of over 50% between pH 3.0 and 5.0 for 60 min. The enzyme was activated by Ca2+ and inhibited by Zn2+. The enzyme was able to hydrolyze sodium phytate with a Km=0.72 mM, Vmax= 94.55 U/mg of protein. The crude extract containing phytase was dried using Spray Dryer with different adjuvants. Soybean meal and corn meal allowed the best recovery of phytase activity 60% and 59.5%, respectively. Considering the use of these two adjuvants, the optimum pH of activity for phytase in the dry extract was 4.5 and 8.5, respectively, and the optimum of temperature of 45-50 °C. When used corn meal, the stability was maintained above 90% at pH 2.5-10.0 for 60 min. The dry phytase (corn meal) was applied to the feed...
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Липовська, Вікторія Вікторівна, Виктория Викторовна Липовская, Viktoriia Viktorivna Lypovska, and М. О. Крамар. "Епідеміологічна ситуація по захворюваності дітей на мікроспорію у північно-східному регіоні України." Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41994.

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Мікроспорія відноситься до найбільш поширених захворювань мікотичної етіології у педіатричній практиці, займаючи друге місце за розповсюдженістю в світі та Україні після мікозів стоп. Мікоз характеризується високою контагіозністю та швидким поширенням. Для запобігання розповсюдження захворювання серед дітей необхідно володіння лікарями інформацією про епідеміологічну ситуацію щодо захворюваності на мікотичні інфекції, зокрема на мікроспорію.

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Морозова, О. О., and В. Е. Коваленко. "Порівняльна характеристика захворювання на мікроспорію у деяких країнах світу та в Україні." Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42211.

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У сучасній дерматологічній практиці грибкові захворювання посідають одне з провідних місць, не поступаючись за кількістю жодному дерматозу. За різними оцінками, на частку мікозів припадає від 37 до 42% від усіх хвороб шкіри. Найбільш актуальною серед грибкових хвороб є мікроспорія, яка зустрічається на всіх континентах (за вийнятком Антарктиди).

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Guyon, Virginie Noelle Veronique. "Molecular study of microspore development in Brassica napus." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387037.

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Naktinskaitė, Lina. "Dermatofito microsporum canis jautrumas dezinfekcinėms medžiagoms." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140305_140350-34848.

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Lietuvoje registruotų dezinfekcinių priemonių: baliklio, TH4+, Safe 4, Ecocid S, formalino, buvo atliktas tyrimas, nustatyti Microsporum canis jautrumą, dezinfektantui. Patogeninio mikromiceto M. canis kolonijos išskirtos iš dermatofitija sergančių kačių.
Experiment was done to determine Microsporum canis sensitivity for disinfectant, using detergents which are registered in Lithuania: bleach , TH4 + , Safe 4 , S ecocide , formalin. Micromycetes pathogenic M. canis colonies isolated from cats which infected by dermatophytosis.

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Hunter, Clifford Paul. "Plant regeneration from microspores of barley Hordeum vulgare L." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/7765.

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Scott, Peter. "The metabolism of sucrose and maltose by barley microspores." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239199.

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Ornela, Pedro Henrique de Oliveira. "Co-purificação e caracterização das fosfatase e fitase alcalinas de Rhizopus microsporus var. microsporus produzidas em fermentação submersa /." Araraquara, 2017. http://hdl.handle.net/11449/151602.

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Orientador: Luis Henrique Souza Guimarães
Banca: Ariela Veloso de Paula
Banca: Hamilton Cabral
Resumo: A investigação biotecnológica, acompanhada da aplicação das enzimas, tem sido realizada em microrganismos para a produção de enzimas para fins industriais. Entre estas enzimas, as fosfatases, responsáveis por hidrolisar ésteres e anidridos de ácido fosfórico, e as fitases microbianas, que catalisam a hidrólise do fitato (mio-inositol hexaquisfosfato) em mio-inositol e fosfato inorgânico, têm sido amplamente utilizadas em diferentes setores como, por exemplo, em experimentos de biologia molecular e na alimentação animal. De acordo com o pH ótimo de reação, as fosfatases são divididas em alcalinas (EC 3.1.3.1) e ácidas (EC 3.1.3.2). As fitases são enzimas que também pertencem à classe das fosfatases, hidrolisando, no entanto, de forma específica, o ácido fítico. Em recentes trabalhos, o fungo filamentoso Rhizopus microsporus var. microsporus apresentou potencialidade na produção de fosfatases e fitases. Diante disto, este estudo visou a produção, a purificação e caracterização da fosfatase e da fitase alcalina produzidas por R. microsporus var. microsporus. No processo de otimização em Fermentação Submersa (FSbm), a maior produção enzimática foi em meio Khanna com 0,4 mM de KH2PO3 e adicionado de 0,5% de farinha de centeio por 76 h, 32ºC, pH 6,3, a 100 rpm. Em colunas cromatográficas, a fosfatase alcalina foi purificada 10 vezes e com recuperação de 13%, e a fitase alcalina foi purificada 86 vezes com recuperação de 167%. A massa molecular nativa da fosfatase e da fitase alcali... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Biotechnological research, accompanied by the application of enzymes, has been carried out in microorganisms for production of enzymes for industrial purposes. Among these enzymes, microbial phosphatases, responsible for hydrolyzing phosphoric acid esters and anhydrides, and phytases, which catalyzes the hydrolysis of phytate (myo-inositol hexaquisphosphate) in myo-inositol and inorganic phosphate, have been widely used in different sectors as, for example, in molecular biology experiments and in animal feed. According to the optimum reaction pH, phosphatases are divided into alkaline (EC 3.1.3.1) and acidic (EC 3.1.3.2). Phytases are enzymes that also belong to the class of phosphatases, however, hydrolyzing phytic acid. In recent works, the filamentous fungus Rhizopus microsporus var. microsporus presented potential for production of phosphatases and phytases. In view of this, this study aimed at the production, purification and characterization of phosphatase and alkaline phytase produced by R. microsporus var. microsporus. In the optimization of Submerged Fermentation (FSbm), the highest enzymatic production was in Khanna medium with 0.4 mM KH2PO3 and added with 0.5% rye flour for 76 h, 32ºC, pH 6.3, at 100 rpm. In chromatographic columns, alkaline phosphatase was purified 10 folds and recovered at 13%, and alkaline phytase was purified 86 folds with recovery of 167%. The native molecular mass of alkaline phosphatase and phytase produced by R. microsporus var. microsporus... (Complete abstract click electronic access below)
Mestre

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Zhao, Jiping. "Induction and mechanism of Brassica napus cv. Topas microspore embryogenesis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq20600.pdf.

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Ili´c-Grubor, Katica. "A novel approach to microspore embryogenesis in Brassica Napus L." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ32787.pdf.

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Stadnyk, Kimberly D. "Improvement on the microspore culture methodology for Brassica rapa canola." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ41780.pdf.

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Daniels, Stephen J. "Studies in the production of microspore-derived haploids in lupin." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266148.

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Camacho, Fernández Carolina. "Microspore embryogenesis: cell wall dynamics and reprogramming of cell fate." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/163698.

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[ES] Los dobles haploides son una gran herramienta para la mejora genética de híbridos debido a que se puede alcanzar la homocigosis completa en una sola generación. Entre las técnicas usadas para obtener estas plantas, la inducción de la embriogénesis de microsporas, mediante el cultivo de anteras o de microsporas, es la más eficiente y la más usada. La embriogénesis de microsporas es también un ejemplo de totipotencia de las células vegetales gracias a su habilidad de reprogramar su desarrollo gametofítico hacia una ruta esporofítica, donde las células proliferan de forma organizada para crear un nuevo organismo. Como en muchos otros procesos in vitro, las condiciones de cultivo deben ser optimizadas para incrementar la eficiencia. En la presente Tesis Doctoral, hemos usado dos especies como sistemas experimentales para estudiar y optimizar el cultivo de microsporas. Por un lado, usamos berenjena (Solanum melongena) como un ejemplo de cultivo de importancia económica en el que los protocolos todavía tienen mucho margen de mejora. La optimización de la densidad celular y los reguladores de crecimiento han demostrado ser útiles para modificar la eficiencia del cultivo de microsporas de berenjena. Por otra parte, hemos utilizado el cultivo de microsporas de Brassica napus para estudios básicos puesto que ha sido ampliamente usado como modelo para entender procesos celulares que ocurren durante este cambio en el desarrollo. Se detalla un protocolo estandarizado para el cultivo de microsporas de B. napus, el cual ha sido utilizado en todos los cultivos en esta Tesis para explorar una serie de procesos y estructuras celulares potencialmente implicados en el cambio de desarrollo hacia embriogénesis. Estos procesos incluyen estrés del retículo endoplásmico, muerte celular programada, autofagia y estructura y composición de la pared celular. Estudiamos en paralelo el cultivo de microsporas de dos genotipos de B. napus con diferente respuesta androgénica en condiciones estándar y añadiendo Tricostatina A, un modulador epigenético que ha mostrado ser beneficioso para la respuesta androgénica en algunos casos. En conjunto, esta Tesis representa un avance en la optimización del cultivo de microsporas en estas especies y arroja luz sobre el papel de algunos procesos en el contexto de embriogénesis de microsporas.
[CA] Els dobles haploides són una gran eina en millora vegetal per a la producció d'híbrids, a causa de la seua total homozigosi, que es pot aconseguir en només una generació in vitro. Entre les diverses tècniques que s'utilitzen per tal d'obtenir aquestes plantes, la inducció de l'embriogènesi de microspores, mitjançant cultiu d'anteres o microspores, és la més comuna i eficient. L'embriogènesi de microspores també és un exemple de la totipotència de les cèl·lules vegetals, capaços de reprogramar-se d'una via gametofítica a una via esporofítica, on proliferen de manera organitzada per crear un nou organisme. Com en moltes altres tecniques in vitro, s'han d'optimitzar les condicions del cultiu per tal d'augmentar l'eficiència. En la present Tesi Doctoral, hem utilitzat dues espècies de plantes com a sistemes experimentals per estudiar i optimitzar el cultiu de microspores. Per una banda, hem utilitzat l'albergínia (Solanum melongena) com a exemple de cultiu d'importància econòmica on els protocols encara tenen marge per a l'optimització. La optimització de la densitat de cèl·lules en cultiu i la concentració de reguladors de creixement van demostrar ser útils per modificar l'eficiència de la resposta dels cultius de microspores d'albergínia. D'altra banda, hem utilitzat cultius de microspores de Brassica napus principalment per a estudis bàsics, ja que s'utilitza àmpliament com a model per entendre els processos cel·lulars que es produeixen durant aquest canvi de desenvolupament. Es detalla un protocol estandarditzat per al cultiu de microspores de B. napus, que s'ha utilitzat en tots els cultius inclosos en aquesta Tesi per explorar una sèrie de processos i estructures cel·lulars potencialment implicades en el canvi de desenvolupament cap a l'embriogènesi. Aquests inclouen l'estrès del reticle endoplasmàtic, la mort cel·lular programada, l'autofàgia i l'estructura i composició de la paret cel·lular. Vam estudiar en paral·lel cultius de microspores de dos genotips de B. napus amb diferent resposta androgènica, cultivats en condicions estàndard i afegint-hi Tricostatina A, un modulador epigenètic que s¿ha demostrat beneficiós per a la resposta androgènica en alguns casos. En conjunt, aquesta Tesi representa un avanç en l'optimització dels cultius de microsporas en aquestes espècies i aporta llum sobre el paper d'alguns processos en el context de l'embriogènesi de microspores.
[EN] Doubled haploids are a great tool for hybrid breeding due to their complete homozygosity achievable in only one in vitro generation. Among the several techniques used to obtain these plants, induction of microspore embryogenesis, via anther or microspore culture, is the most common and efficient approach. Microspore embryogenesis is also an example of totipotency of plant cells due to their ability to reprogram themselves from a gametophytic to a sporophytic pathway, where cells proliferate in an organized way to create a new organism. As in many other in vitro procedures, culture conditions must be optimized in order to increase efficiency. In the present Doctoral Thesis, we used two plant species as experimental systems to study and optimize microspore culture. On one hand, we used eggplant (Solanum melongena) as an example of economically important crop where protocols have still room for optimization. Optimization of cell density and growth regulators demonstrated to be useful to modify the efficiency of eggplant microspore cultures. On the other hand, we used B. napus microspore cultures principally for basic studies since it is widely used as a model to understand cellular processes occurring during this developmental switch. A standardized protocol for Brassica napus microspore culture is detailed, which was used in all the cultures included in this Thesis to explore a series of processes and cellular structures potentially involved in the developmental switch towards embryogenesis. These included endoplasmic reticulum stress, programmed cell death, autophagy, and cell wall structure and composition. We studied in parallel microspore cultures from two B. napus genotypes with different androgenic response cultured in standard conditions and adding Trichostatin A, a epigenetic modulator shown to be beneficial for the androgenic response in some cases. Together, this Thesis represents an advance in the optimization of microspore cultures in these species, and sheds light on the role of some processes within the context of microspore embryogenesis.
Thanks are due to the Electron Microscopy Service of Universitat Politècnica de València, Marisol Gascón (IBMCP Microscopy Service). This work was supported by grant AGL2017-88135-R to JMSS from MICINN jointly funded by FEDER and by a Marie Skłodowska-Curie Individual Fellowship (656579) to PC-M This work was supported by grant AGL2017-88135-R to JMSS from MINECO jointly funded by FEDER.
Camacho Fernández, C. (2021). Microspore embryogenesis: cell wall dynamics and reprogramming of cell fate [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/163698
TESIS

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Bélanger, Sébastien. "Caractérisation génomique et transcriptomique de la microspore embryogénique chez l'orge." Doctoral thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/33304.

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L’androgenèse est une biotechnologie végétale utilisée pour fixer le bagage génétique des plantes en une seule génération. Elle repose sur la capacité d’un grain de pollen immature, la microspore, à restaurer sa totipotence cellulaire végétale et se dédifférencier puis s’engager dans la voie de l’embryogenèse. Or, on observe que la capacité de la microspore à s’engager dans l’embryogenèse est génétiquement variable. En dépit des nombreux avantages qu’elle présente, l’androgenèse entraîne souvent une conséquence indésirable, soit une distorsion de la ségrégation (DS) chez les populations issues de cette biotechnologie. Ma thèse porte sur l’étude (i) du transcriptome de la microspore en transition entre la voie de développement du grain de pollen et celle de l’androgenèse et (ii) de la DS pour déterminer quand la DS survient dans le processus et où elle affecte le génome. J’ai utilisé l’orge comme espèce modèle pour mon étude. L’analyse transcriptomique a été réalisée sur la microspore isolée de l’anthère à trois stades, soit avant (jour 0) et immédiatement après (jours 2 et 5) l'application d'un traitement de stress visant à induire la voie de l’androgenèse. Je me suis intéressé à deux catégories de gènes; soit les gènes exprimés exclusivement à un stade précis et les gènes exprimés différemment lors de l’initiation de l’androgenèse. J’ai pu identifier des gènes exprimés exclusivement dans la microspore au jour 0 (11), 2 (34) ou 5 (367). Au jour 5, j’ai constaté l’induction de nombreux gènes codant pour des FT et des gènes impliqués dans la synthèse ou la transduction du signal de nombreux régulateurs de croissance. L’analyse des gènes exprimés différemment m’a permis d’identifier certains processus métaboliques qui sont activés/réprimés lors du passage de la microspore du jour 0 au jour 2 et du jour 2 au jour 5. Les gènes exprimés exclusivement à un stade précis du développement pourraient servir de marqueurs moléculaires indicateurs de la performance en androgenèse pour optimiser les protocoles de culture. Ensuite, la DS a été étudiée par une approche de génotypage à l’échelle génomique. J’ai d’abord développé une méthodologie d’analyse génotypique novatrice, reproductible et précise pour étudier la fréquence allélique sur un échantillon en composite. Cette méthode m’a permis d’étudier la fréquence allélique chez 1) des échantillons de microspores (avant et après l’application d’un stress), 2) des embryons et 3) des plantes régénérées. J’ai montré que la DS survenait à la fois lors du développement des embryons et la régénération des plantes. Aucune DS n’a été observée chez les échantillons de microspores. Mes résultats montrent que la sélection engendrant la DS s’opère au cours de la culture in vitro. Toujours à l’aide de cette méthode de génotypage en composite, j’ai identifié et comparé la fréquence et l’étendue de la DS chez 12 populations de lignées haploïdes doublées (HD). Dans cette seule étude, un plus grand nombre de populations de lignées HD (12) ont été caractérisées que ce qui avait été fait dans la somme de toutes les études antérieures dans la littérature scientifique. Nous avons montré que les régions de distorsion de ségrégation différaient beaucoup quant à leur position, leur étendue et l’amplitude de la distorsion d’un croisement à l’autre. La connaissance de ces allèles permettrait de prédire le potentiel androgénique des génotypes dans un programme de sélection. Mes travaux de thèse élèvent à l’ère des «omics» la recherche chez la microspore d’orge dans le système de l’androgenèse. À une échelle sans précédent, mon étude transcriptomique explore et décrit les changements d’expression génique au cours de la transition développementale de la microspore. Mon étude génomique identifie quand s’exerce la sélection engendrant la distorsion de la ségrégation des allèles dans ce système et décrit quelles régions chromosomiques sont affectées par cette distorsion. À la lumière de mes résultats, dans le dernier chapitre, je propose certaines pistes de recherche pour poursuivre l’étude des mécanismes moléculaires dirigeant la transition développementale de la microspore en androgenèse et pour développer des outils de génotypage afin d’utiliser la DS comme un outil d’amélioration génétique.
Androgenesis is a plant biotechnology used to fix the genetic background of plants in a single generation. This is based on the ability of an immature pollen grain, the microspore, to restore its totipotency, to dedifferentiate and then to engage in the path of embryogenesis. However, it is observed that the ability of the microspore to engage in embryogenesis is genetically variable. Despite the many desirable attributes of androgenesis, an undesirable side - effect is the segregation distortion (SD) encountered in populations resulting from this biotechnology. My thesis focuses on (i) the study of the transcriptome of microspores undergoing a developmental transition from the pollen - grain pathway towards embryogenesis and (ii) to identify when SD arises in the process and in which genomic regions it occurs. I used barley as a model species for my studies. Transcriptomic analysis was performed on microspores isolated from anthers at three stages corresponding to the microspore before (day 0) and immediately after (days 2 and 5) the application of a stress treatment aimed at inducing embryogenesis. I was interested in two categories of genes: those expressed exclusively at a specific stage of microspore development and those that were differentially expressed during the initiation of androgenesis. I was able to identify genes expressed exclusively in the microspore on day 0 (11), 2 (34) or 5 (367). On day 5, I found the induction of many genes encoding transcription factors (T Fs) in addition to genes involved in the synthesis or signal transduction of many growth regulators. The analysis of differentially expressed genes allowed me to identify certain metabolic processes that were activated/repressed during microspore development from day 0 to 2 and from day 2 to 5. Genes expressed exclusively at a specific stage of development could serve as molecular markers indicative of the performance in androgenesis to optimize isolated microspore culture protocols. Then, SD was studied using a whole - genome genotyping approach. I first developed an innovative, reproducible and accurate genotypic analysis methodology to determine allelic frequency on pooled samples. This method was then used to estimate allelic frequencies in samples of microspores (before and after the application of stress), embryos and regenerated plants. I showed that SD arises during both the development of embryos and the regeneration of plants. No SD was observed in samples of microspores. My results show that the selective forces promoting SD act during in vitro culture. Still using the same genotyping method performed on pooled samples, I identified and compared the frequency and extent of SD in 12 populations of doubled haploid lines (DH). A greater number of DH (12) populations were characterized in my study alone than the sum of all previous studies in barley. I showed that segregation distortion regions greatly differ in their position, extent, and magnitude in different DH populations. Knowledge of these alleles would be useful to predict the androgenic potential of a genotype in a breeding program. My dissertation has allowed research into barley microspores, or more widely androgenesis, to enter into the “omics” era. On an unprecedented scale, my transcriptomic study explores and describes the gene expression changes that occur during the developmental transition that the microspore undergoes in the course of androgenesis. My genomic study identifies when the selection (producing SD) arises in this system and describes which chromosomal regions are affected by this distortion. In light of my findings, in the final chapter I propose some lines of research to further study the molecular mechanisms driving the developmental transition from microspores to embryos and to develop genotyping tools to use SD as a genetic improvement tool.

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Triggs, Heidi M. "Haploid production and genetic transformation of wheat (Triticum aestivum L.)." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243689.

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Poulet, Blandine. "Microsporum persicolor : affections humaines ; etude chez les petits rongeurs." Nancy 1, 1991. http://www.theses.fr/1991NAN11146.

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18

Rivas, Sendra Alba. "Calcium and cell wall dynamics during microspore embryogenesis and double haploid production in rapeseed and eggplant." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/85548.

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Androgenesis induction is an experimental procedure by which microspores are diverted from their original gametophytic pathway towards embryogenesis by applying specific stresses in vitro. It allows for the production of doubled haploid (DH) pure lines through anther culture or isolated microspore culture followed by chromosome doubling. DH technology is interesting for both basic research and plant breeding. In this Thesis, we studied microspore embryogenesis with two parallel approaches: (I) an applied study directed to the development of the first eggplant (Solanum melongena) highly embryogenic line and the improvement of the efficiency of eggplant microspore cultures; and (II) a fundamental research study focused on the relationship between microspore embryogenesis ability, intracellular Ca2+ levels and the dynamics of callose and cellulose deposition for cell wall formation in microspore-derived structures, using rapeseed (Brassica napus) as a model species. As an applied research, we developed and evaluated an eggplant DH population from a commercial hybrid, and identified and characterized the first eggplant highly androgenic DH line (DH36), which may be used to facilitate the study of eggplant androgenesis and for both basic and applied research. In addition, we evaluated different factors involved in microspore embryogenesis induction efficiency in eggplant and optimized the regeneration protocol for DH production via microspore culture. Together, the applied research on eggplant microspore embryogenesis made in this Thesis resulted in the most efficient protocol existing to date for DH production in eggplant. As a fundamental research, we studied the dynamics of Ca2+ during in vivo microsporogenesis and microgametogenesis, as well as during the first stages of in vitro-induced microspore embryogenesis, establishing a link between microspore embryogenesis and changes in Ca2+ levels and subcellular distribution. In addition, we studied the deposition of callose and cellulose during the first stages of microspore embryogenesis and demonstrated that the abnormally increased callose deposition and the inhibition of cellulose deposition observed in embryogenic microspores is most likely caused by a transient increase in the intracellular Ca2+ levels that occurs right after microspore induction. We also found that this particular dynamics of callose and cellulose deposition is related to microspore embryogenesis ability, and is essential for proper progression and success of microspore embryogenesis. In summary, the research made in this Thesis helps to further understand the basis underlying microspore embryogenesis and cell totipotency, and to apply the powerful DH technology to an economically important crop such as eggplant.
La inducción de androgénesis es un procedimiento experimental en el cual las microsporas se desvían de su vía gametofítica original hacia embriogénesis, mediante la aplicación de estreses específicos in vitro. Este fenómeno permite la producción de líneas puras dobles haploides (DH) mediante cultivo de anteras o cultivo de microsporas aisladas seguidos de duplicación cromosómica. La tecnología DH es interesante tanto para la investigación básica como para su aplicación a la mejora genética vegetal. En esta Tesis se estudia la embriogénesis de microsporas y la obtención de DHs con dos enfoques paralelos: (I) un estudio aplicado dirigido al desarrollo de la primera línea de berenjena (Solanum melongena) con alta respuesta androgénica y a la mejora de la eficiencia de los cultivos de microsporas de berenjena; y (II) un estudio de investigación básica centrado en la relación entre la habilidad para la embriogénesis de microsporas, los niveles intracelulares de Ca2+ y la dinámica de la deposición de calosa y celulosa para la formación de paredes celulares en estructuras derivadas de microsporas, utilizando como especie modelo la colza (Brassica napus). Como investigación aplicada, se desarrolló y evaluó una población DH de berenjena a partir de un híbrido comercial, y se identificó y caracterizó la primera línea DH altamente androgénica de berenjena (DH36), que puede usarse para facilitar el estudio de la androgénesis en berenjena y para otros estudios aplicados o básicos. Además, se evaluaron diferentes factores implicados en la eficiencia de la inducción de embriogénesis de microsporas en berenjena, y se optimizó el protocolo de regeneración para la producción de DH mediante cultivo de microsporas. En conjunto, la investigación aplicada sobre la embriogénesis de microsporas realizada en esta Tesis proporciona el protocolo más eficiente existente hasta la fecha para la producción de DH en berenjena. Como investigación fundamental, se estudió la dinámica del Ca2+ durante la microsporogénesis y la microgametogénesis in vivo, así como durante las primeras etapas de la embriogénesis de microsporas inducida in vitro, y se estableció un vínculo entre la embriogénesis de microsporas y los cambios en el nivel y distribución intracelular de Ca2+. Además, se estudió la deposición de calosa y celulosa durante las primeras etapas de la embriogénesis de microsporas y se demostró que la excesiva deposición de calosa y la inhibición de la deposición de celulosa, exclusivas de las microsporas embriogénicas, están causadas por el aumento transitorio de Ca2+ intracelular que se produce justo tras la inducción. Hemos demostrado que esta particular dinámica de la deposición de calosa y celulosa está relacionada con la capacidad androgénica, y que es fundamental para la correcta progresión y éxito de la embriogénesis de microsporas. En resumen, la investigación realizada en esta Tesis ayuda a comprender mejor la base de la embriogénesis de microsporas y de la totipotencia celular, y a aplicar la potente tecnología DH a un cultivo económicamente importante como es la berenjena.
La inducció d'androgènesi és un procediment experimental en el qual les microspores es desvien de la seua via gametofítica original cap a un nou destí embriogènic, mitjançant l'aplicació d'estressos específics in vitro. Aquest fenomen permet la producció de línies pures dobles haploides (DH) mitjançant cultiu d'anteres o cultiu de microsporas aïllades seguits de duplicació cromosòmica. La tecnologia DH és interessant tant per a la recerca bàsica com per a la seua aplicació a la millora genètica vegetal. En aquesta Tesi s'estudia l'embriogènesi de microspores i l'obtenció de DHs amb dos enfocaments paral·lels: (I) un estudi aplicat dirigit al desenvolupament de la primera línia d'albergina (Solanum melongena) amb alta resposta androgènica i a la millora de l'eficiència dels cultius de microspores d'albergina; i (II) un estudi de recerca bàsica centrat en la relació entre la capacitat per a l'embriogènesi de microspores, els nivells intracel·lulars de Ca2+ i la dinàmica de la deposició de cal·losa i cel·lulosa per a la formació de parets cel·lulars en estructures derivades de microsporas, utilitzant com a espècie model la colza (Brassica napus). Com a recerca aplicada, es va desenvolupar i avaluar una població DH d'albergina a partir d'un híbrid comercial, i es va identificar i caracteritzar la primera línia DH altament androgènica d'albergina (DH36), que pot usar-se per a facilitar l'estudi de l'androgènesi en albergina i per a altres estudis aplicats o bàsics. A més, es van avaluar diferents factors implicats en l'eficiència de la inducció d'embriogènesi de microspores en albergina, i es va optimitzar el protocol de regeneració per a la producció de DH mitjançant cultiu de microspores. En conjunt, la recerca aplicada sobre l'embriogènesi de microspores realitzada en aquesta Tesi proporciona el protocol més eficient existent fins avui per a la producció de DH en albergina. Com a recerca fonamental, es va estudiar la dinàmica del Ca2+ durant la microsporogènesi i la microgametogènesi in vivo, així com durant les primeres etapes de l'embriogènesi de microspores induïda in vitro, i es va establir un vincle entre l'embriogènesi de microspores i els canvis en el nivell i distribució intracel·lular de Ca2+. A més, es va estudiar la deposició de cal·losa i cel·lulosa durant les primeres etapes de l'embriogènesi de microspores i es va demostrar que l'excessiva deposició de cal·losa i la inhibició de la deposició de cel·lulosa, exclusives de les microspores embriogèniques, estan causades per l'increment transitori del Ca2+ intracel·lular que es produeix just després de la inducció. Hem demostrat que aquesta particular dinàmica de la deposició de cal·losa i cel·lulosa està relacionada amb la capacitat androgènica, i que és fonamental per a la correcta progressió i èxit de l'embriogènesi de microspores. En resum, la recerca realitzada en aquesta Tesi ajuda a comprendre millor la base de l'embriogènesi de microspores i de la totipotència cel·lular, i a aplicar la potent tecnologia DH a un cultiu econòmicament important com és l'albergina.
Rivas Sendra, A. (2017). Calcium and cell wall dynamics during microspore embryogenesis and double haploid production in rapeseed and eggplant [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/85548
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Roehe, Carlos. "Gatos portadores de dermatófitos na região metropolitana de Porto Alegre - RS, Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/95141.

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A dermatofitose é a zoonose micótica mais difundida mundialmente e os animais domésticos são os principais reservatórios dos dermatófitos zoofílicos que, em alguns países, são causadores mais frequentes da doença em humanos do que as espécies antropofílicas. Especificamente em relação ao Microsporum canis, principal espécie zoofílica nas zonas urbanas, pouco sucesso foi obtido com a produção de vacinas para seu controle. Os objetivos dessa pesquisa foram verificar a ocorrência gatos clinicamente sadios portadores de dermatófitos na região metropolitana de Porto Alegre e, também, analisar estatisticamente a influência de fatores como idade, sexo, raça e acesso à rua. Amostras foram obtidas do pelame de 191 gatos sem sinais clínicos de dermatoses após fricção dos pelos (face, região pré-auricular, dorso, cauda e membros) que foram semeadas em ágar Sabouraud acrescido de cloranfenicol e ciclohexamida e incubadas a 27°C por até 21 dias. A possibilidade da associação entre as variáveis preditoras e a variável resposta foi avaliada através de um modelo de regressão logística univariado. Somente espécies de Microsporum (8,4%) foram isoladas de amostras positivas: M. canis (5,8%) e M. gypseum (2,6%). Em 15 (7,8%) das amostras não ocorreu crescimento fúngico. Nos restantes 160 (83,8%) cultivos foram isolados diversos fungos saprotróficos: filamentosos hialinos (Penicillium sp., Aspergillus sp., Acremonium sp., Chrysosporium sp., Paecilomyces sp., Fusarium sp. e Scopulariopsis sp.); filamentosos dematiáceos ( Cladosporium sp., Alternaria sp. e Curvularia sp.); zigomicetos (Rhizopus sp. e Mucor sp.) e leveduras (Malassezia sp. e Candida sp.). Foi observado um maior risco relativo para o isolamento de dermatófito quando o animal era do sexo masculino e teve acesso à rua em uma magnitude de 3,43 e 3,52, respectivamente. Não foi identificado nenhum fator protetivo na análise multivariada. O modelo final teve poder discriminatório de 72%. Ainda são poucas as informações sobre o complexo mecanismo de infecção e a susceptibilidade dos animais, mas o isolamento fúngico de gatos sadios aliado a dados epidemiológicos são importantes ferramentas para o diagnóstico e tratamento desta micose. Os resultados obtidos corroboram estudos similares realizados em regiões metropolitanas de outros países. É enfatizada a possibilidade de contágio humano a partir de gatos assintomáticos e a necessidade da adoção de medidas profiláticas para reduzir a disseminação dos dermatófitos.
Dermatophytoses are in the list of the most frequent skin diseases of pets and livestock all over the world. Contagiousness among animal communities, difficulty in implementing control measures, and the eventual transmition of animal ringworm to people explain its great importance. A wide variety of dermatophytes have been isolated from animals, but a few zoophilic species are responsible for the majority of the cases. Microsporum canis is one of these and in some countries seems to cause a high proportion of human infections, outnumbering classical ringworm anthropophilic dermatophytes. So far, a safe and efficient vaccine is not available for protecting cats and dogs exposed to M. canis. The objective of this study is to survey dermatophytes in clinically normal cats in the metropolitan area of Porto Alegre, south of Brazil, and weight the possible influence of age, sex, breed and living conditions in the presence of these fungi. Samples were obtained from 191 cats with no skin disease after brushing the body (head, neck, dorsum, limbs and tail) and incubated on Sabouraud dextrose agar with chloramphenicol and cyclohexamide at 27°C for up to 21 days. The possibility of association between predictors variables and a variable answer was evaluated by an univariate logistic regression model. Only Microsporum species, (8,4%) were isolated from positive specimens: M. canis (5,8%) and M. gypseum (2,6%). On 15 samples (7,8%) there was no fungal growth. Of the remaining 160 samples (83,8%), several saprotrophic fungi were isolated: hyaline filamentous fungi (Penicillium sp., Aspergillus sp., Acremonium sp., Chrysosporium sp., Paecilomyces sp., Fusarium sp. and Scopulariopsis sp.); dematiaceous filamentous fungi (Cladosporium sp., Alternaria sp. and Curvularia sp.); Zygomycetes (Rhizopus sp. and Mucor sp.) and yeasts (Malassezia sp. and Candida sp.). It was observed an higher relative risk for the isolation of dermatophyte when the cat was male and was allowed to walk outdoors in a magnitude of 3.43 and 3.52, respectively. The multivariate analysis did not identify any protective factor against dermatophytosis. The final model had a discriminatory power of 72%. There are few informations about the complex mechanisms of infection and susceptibility of the animals, but fungal isolation from healthy cats associated with epidemiological features are important tools in the diagnosis and management of the problem. Results of this research are similar to others conducted around urban areas of different countries across the world. It is emphasized that human beings can be contaminated from apparently healthy cats and the author stresses the necessity of prophylactic measures in order to reduce the spread of dermatophytosis.

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Redha, Amina. "Induction and analysis of chromosome doubling of microspore derived wheat haploids /." Zürich, 1998. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12855.

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21

Boutilier, Kim. "Isolation and characterization of molecular markers for Brassica napus microspore embryogenesis." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6474.

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Brassica napus microspores can be diverted from pollen development toward haploid embryo formation in culture by subjecting them to a heat stress treatment. This switch in developmental pathways has been shown to be accompanied by the induction of high levels of napin seed storage protein gene expression (DeMoor, 1992). Specific members of the napin multigene family that were expressed at this time were cloned from a cDNA library prepared from microspores that had been induced to undergo embryogenesis. The majority of napin clones represented three members (BnmNAP2, BnmNAP3 and BnmNAP4) that, along with a previously isolated napin genomic clone (BngNAP1), are members of the highly conserved BnmNAP subfamily of napin genes. DNA gel blot analysis, using a subfamily-specific probe, suggested that this subfamily may consist of up to 5 members. RNA gel blot analysis, also using the subfamily-specific probe, indicated that the BnmNAP subfamily was also expressed during embryo development. BnmNAP mRNA was detected as early as the globular stage of development in microsporic embryos, but not until the late torpedo/early cotyledon stage of development in zygotic embryos. A BngNAP1 promoter-$\beta$-glucuronidase (GUS) gene fusion was introduced into B. napus and Nicotiana tabacum (tobacco) plants in order to examine the spatial and temporal pattern of expression of one member of the BnmNAP subfamily. The BngNAP1-GUS construct was shown to be highly expressed in microspores that had been induced to undergo embryogenesis, but was not expressed in microspores continuing pollen development in culture. Furthermore, BngNAP1-directed GUS activity appeared to be predominantly localized in those microspores that have been shown to have the greatest potential to form embryos in culture. Fluorogenic and histochemical analysis of developing microsporic and zygotic embryos of B. napus indicated that the BngNAP1-GUS fusion was expressed as early as the globular stage of development. GUS activity was first detected in the micropylar region of the future embryonic axis and continued to spread upward during subsequent stages of development. In tobacco, GUS activity was first detected in the endosperm of seeds containing globular stage embryos. GUS activity did not begin to accumulate in tobacco embryos until the early heart stage of development, where it appeared as a band in the middle of the embryo, just under the lobes of the emerging cotyledons. This activity continued to spread outward in both directions as development proceeded. Thus the timing, but not the spatial localization, of BngNAP1-directed GUS expression was maintained in transgenic tobacco.

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Cimò, Giuseppe. "Ploidy manipulation for genetic improvement in some Mediterranean fruit crops." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/79874.

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Plant breeding is focused on selection of new genotypes with improved traits. Conventional methods based on hybridization and those based on biotechnology (somatic hybridization, genetic transformation, ploidy manipulation, etc.) are used to create novel genetic variations. Biotechnology provides powerful tools for plant breeding, for instance, haploid technology allows achievement of homozygous lines from heterozygous parents in one step, which reduces significantly the time required by conventional methods. Concerning woody species, characterized by self-incompatibility, long juvenile period and high degree of heterozygosity, this technique is the only way to get homozygous lines. Haploid plants are of great interest for breeding and genomic studies, being used in mutation research, genetic analysis, genome mapping and gene transfer. Gametic embryogenesis, based on cellular totipotency, produces an embryo from an immature gamete, by switching its developmental pathway from gametophytic to sporophytic. This research is focused on inducing gametic embryogenesis in two important Mediterranean fruit crops: almond (Prunus dulcis Mill.) via in vitro anther culture and mandarin (Citrus reticulata Blanco) via isolation and microspore culture. Also ploidy manipulation was applied to loquat (Eriobotrya japonica (Thunb.) Lindl.) for getting genotypes whit different ploidy levels. The experiments were carried out through years 2014, 2015 and 2016 at the 'Università degli Studi di Palermo' (UNIPA) as well as at the 'Instituto Valenciano de Investigaciones Agrarias' (IVIA). Regarding the almond anther culture, formation of calli and production of embryos was achieved through the direct embryogenesis route. On then other hand, early embryo regeneration is reported, for the first time, from isolated microspore culture of mandarin, 'Mandarino Tardivo di Ciaculli'. Our results report the evidence of gametic embryogenesis and the production of homozygous regenerants in almond and mandarin, two species extremely recalcitrant to microspore embryogenesis. However, the results are affected by many factors that need further studies to better understand the embryogenic development and to increase the rate of embryo achievement. Moreover, another biotechnological tool (ploidy manipulation) was also applied for implementing the IVIA loquat breeding program. Polyploid plants are of great interest in this species, due to its potential for producing seedless genotypes via direct use of triploids or crosses between tetra and diploids. Aimed at obtaining new loquat genotypes, with different ploidy levels (polyploids), colchicine was applied to seeds before germination, to induce chromosome duplication. A total of three triploids (3x) and one tetraploid (4x) were obtained.
La mejora genética tiene como objetivo la selección de nuevos genotipos con mejores características. Los métodos de mejora convencional basados en hibridaciones y aquellos basados en Biotecnología (hibridación somática, transformación genética, manipulación de la ploidía, etc.) se utilizan para obtener nueva variación genética. La Biotecnología proporciona herramientas poderosas en mejora genética, por ejemplo, la obtención de haploides permite obtener líneas homocigotas en un solo paso, disminuyendo significativamente el tiempo requerido usando métodos convencionales. Respecto a especies leñosas, caracterizadas por autoincompatibilidad floral, largo período juvenil y alto grado de heterocigosidad, esta técnica es el único método de obtención de líneas homocigotas. Los genotipos haploides tienen un alto interés en estudios genómicos, siendo utilizados en estudios de mutaciones, análisis genéticos, mapeo genético y transferencia genética. Este estudio tiene como objetivo la inducción de embriogénesis gamética en dos especies mediterráneas muy importantes: el almendro (Prunus dulcis Mill.) por medio de cultivo in vitro de anteras y el mandarino (Citrus reticulata Blanco) por medio de aislamiento de microesporas. Además, se ha estudiado la obtención de poliploides en níspero (Eriobotrya japonica (Thunb.) Lindl.) con el objetivo de obtener genotipos con diversos niveles de ploidía. Los experimentos se llevaron a cabo en los años 2014, 2015 y 2016 en la 'Università degli Studi di Palermo' (UNIPA) y en el 'Instituto Valenciano de Investigaciones Agrarias' (IVIA). Respecto al cultivo de anteras en almendro, la formación de callos y producción de embriones se obtuvo mediante embriogénesis directa. Por otro lado, se ha conseguido regenerar por primera vez embriones a partir de microesporas aisladas en el cultivar de mandarino 'Mandarino Tardivo di Ciaculli'. Los resultados obtenidos muestran que la embriogénesis gamética y la regeneración de embriones homocigótos en almendro y mandarino, dos especies extremadamente recalcitrantes para la embriogenésis a partir de microesporas, es posible. Sin embargo, los resultados se ven afectados por muchos factores que necesitan estudios adicionales para comprender mejor el desarrollo embriogénico y para aumentar la tasa de obtención del embriones. Además, otra herramienta biotecnológica (manipulación de la ploidía) se aplicó con el objetivo de implementar el programa de mejora de níspero del IVIA. Las plantas poliploides en esta especie tienen un alto interés, pues podrían permitir la obtención de frutos sin semilla, por medio de la obtención directa de triploides o mediante cruzamiento entre tetraploides y diploides. Con el objetivo de obtener nuevos genotipos de níspero con diferentes niveles de ploidía (poliploides), se aplicó colchicina a semillas sin germinar con el fin de inducir la duplicación cromosómica y se obtuvieron 3 triploides (3x) y un tetraploide (4x).
La millora genètica té com objectiu la selecció de nous genotips amb millors característiques. Els mètodes de millora convencional basats en hibridacions i aquells basats en Biotecnologia (hibridació somàtica, transformació genètica, manipulació de la ploïdia, etc.) s'utilitzen per aconseguir nova variació genètica. La Biotecnologia proporciona eines poderoses en millora genètica, per exemple, l'obtenció d'haploides permet obtenir línies homozigòtiques en un sol pas, disminuint significativament el temps requerit usant mètodes convencionals. Pel que fa a espècies llenyoses, caracteritzades per autoincompatibilitat floral, llarg període juvenil i alt grau d'heterozigosi, aquesta tècnica és l'únic mètode d'obtenció de línies homozigòtiques. Els genotips haploides tenen un alt interès en estudis genòmics, sent utilitzats en estudis de mutacions, anàlisis genètics, mapatge genètic i transferència genètica. Aquest estudi té com objectiu la inducció d'embriogènesi gamètica en dos espècies mediterrànies molt importants: l'ametller (Prunus dulcis Mill.) a través del cultiu in vitro d'anteres i el mandariner (Citrus reticulata Blanco) per mitjà d'aïllament de micròspores. A més a més, s'ha estudiat l'obtenció de poliploides en nespra (Eriobotrya japonica (Thunb.) Lindl.) Amb l'objectiu d'aconseguir genotips amb diversos nivells de ploïdia. Els experiments es van dur a terme en els anys 2014, 2015 i 2016 a la 'Università degli Studi di Palermo' (UNIPA) i a 'l'Institut Valencià d'Investigacions Agràries' (IVIA). Respecte al cultiu d'anteres en ametller, la formació de calls i producció d'embrions es va obtenir mitjançant embriogènesi directa. D'altra banda, s'ha aconseguit per primera vegada la regeneració d'embrions a partir de micròspores aïllades en el conrear de mandariner 'Mandarino Tardivo di Ciaculli'. Els resultats obtinguts mostren que l'embriogènesi gamètica i la regeneració d'embrions homozigotics en ametller i mandariner, dues espècies extremadament recalcitrants per l'embriogènesi a partir de micròspores, és possible. No obstant això, els resultats es veuen afectats per molts factors que necessiten estudis addicionals per entendre millor el desenvolupament embriogènic i per augmentar la taxa d'obtenció dels embrions. A més, una altra eina biotecnològica (manipulació de la ploïdia) es va aplicar amb l'objectiu d'implementar el programa de millora de nespra de l'IVIA. Les plantes poliploides en aquesta espècie tenen un alt interès, ja que podrien permetre l'obtenció de fruits sense llavor, per mitjà de l'obtenció directa de triploides o mitjançant encreuament entre tetraploides i diploides. Amb l'objectiu d'aconseguir nous genotips de nespra amb diferents nivells de ploïdia (poliploides), es va aplicar colquicina a llavors sense germinar per tal d'induir la duplicació cromosòmica i es van obtenir 3 triploides (3x) i un tetraploide (4x).
Cimò, G. (2017). Ploidy manipulation for genetic improvement in some Mediterranean fruit crops [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/79874
TESIS

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23

Gaillard, Antoine. "Régénération et transformation chez le maïs : essais à partir de microspores isolées." Lyon 1, 1992. http://www.theses.fr/1992LYO10072.

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L'utilisation des biotechnologies chez les cereales est dependante de la maitrise d'un systeme de regeneration de plantes a partir de cellules isolees. Les techniques d'isolement de microspores mises au point pour differentes cereales permettent d'obtenir des populations de microspores en qualite et en quantite suffisantes pour permettre leur regeneration et realiser des analyses moleculaires. Chez le mais, les conditions de culture conduisant a la regeneration de plantes a partir de ces microspores ont ete definies. Notamment, il a ete trouve que le stade de developpement des microspores, la duree du pretraitement a 7c de la panicule et la densite de culture influencent fortement la production d'embryons. Ce systeme de culture de microspores de mais permet la caracterisation des stades precoces de l'androgenese par differentes approches cytologiques (coloration directe au dapi et au calcofluor, coloration a l'aps sur les coupes semi-fines, et microinjection de colorant fluorescent). Il a ete possible de selectionner des structures embryogenes derivees de microspores qui representent des cibles favorables pour la transformation par microinjection. Des experiences preliminaires de transformation par la biolistique et par microinjection ont ete realisees. La culture de microspores isolees ouvre des perspectives interessantes dans le domaine des biotechnologies et represente un outil de qualite pour une etude moleculaire des mecanismes de l'embryogenese pollinique. Les essais de transformation montrent la faisabilite de transformer les microspores. Ces travaux s'inscrivent dans le cadre general de la comprehension des processus de regeneration et de controle du transfert de genes chez le mais

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Liu, Weiguo. "Transformation of microspores for generating doubled haploid transgenic wheat (Triticum aestivum L.)." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Dissertations/Fall2004/w%5Fliu%5F120204.pdf.

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Costa, Fernanda Vieira Amorim da. "Determinação da variabilidade genotípica entre isolados de Microsporum canis." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/31757.

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Microsporum canis é um dermatófito zoofílico e o fungo mais frequentemente isolado de cães e gatos, de crianças com tinea capitis e de adultos com tinea corporis. Ainda não se conhece as possíveis variáveis envolvidas no estabelecimento de infecções clínicas ou subclínicas em cães e gatos, assim como os fatores envolvidos na transmissão de M. canis para os seres humanos. Diversas técnicas de biologia molecular falharam em demonstrar variabilidade genética entre diferentes linhagens de M. canis, porém, estudos recentes indicam que a utilização de primers mais discriminatórios, como os marcadores microsatélites, possibilite a detecção de diferentes genótipos de M. canis. Os objetivos deste trabalho de pesquisa foram: identificar e comparar o genótipo de M. canis isolados de cães e gatos sintomáticos e assintomáticos e de seres humanos utilizando marcadores microssatélites e investigar uma possível correlação entre as características genotípicas e dados epidemiológicos de M. canis isolados de cães, gatos e seres humanos. Foram incluídos no estudo isolados de 102 cães e gatos sintomáticos e assintomáticos e de pacientes humanos com tinea nos quais se isolou o M. canis durante os anos de 2006 a 2010. Essas amostras foram provenientes de Curitiba, Porto Alegre, Florianópolis e Cuiabá. Dentre elas, 37 eram de gatos sintomáticos, 35 de gatos assintomáticos, 19 de pacientes humanos sintomáticos, 9 de cães assintomáticos e 2 de cães sintomáticos. A amplificação da região de microsatélites do DNA foi realizada utilizando dois primers, McGT13 e McGT17, a qual possibilitou a formação de grupos de acordo com o grau de similaridade genética baseada no número de repetições nessas duas regiões do DNA do M. canis. Os loci Mc(GT)13 e Mc(GT)17 revelaram 3 e 6 alelos, variando de 2 e 5 repetições de dinucleotídeos dentro de cada locus, respectivamente. Dos 14 genótipos e 5 grandes grupos formados após análise da árvore filogenética gerada pelo método Dc, 1 foi compartilhado por 26 isolados, outro por 21, um por 12 isolados e outros dois com 11 isolados cada um. Outros dois pequenos grupos foram formados com 7 e 5 isolados cada. Os marcadores microssatélites possibilitaram a identificação, o estudo filogenético e a comparação dos isolados de M. canis oriundos de gatos, cães e pacientes humanos incluídos no estudo. Apesar da formação de grupos geneticamente relacionados, não houve correlação entre as linhagens e os dados epidemiológicos analisados entre as isolados, incluindo fonte, sintomatologia, quadro clínico, raça, idade, sexo, moradia e localização geográfica.
Microsporum canis is a zoophilic dermatophyte and the most commonly isolated fungi from dogs, cats, children with tinea capitis and adults with tinea corporis. There are unknown variables in establishment of clinical or subclinical infection in dogs and cats and also in M. canis transmission to humans. Several molecular techniques failed to show genetic variability between different strains of M. canis, but recent studies indicate that the use of more discriminatories primers, as microsatellite markers, may detect different genotypes of this dermatophyte. This study has as objectives to identify and compare M. canis strains genotype isolated from symptomatic and asymptomatic dogs and cats and from people with dermatophytosis using microsatellite technique and to investigate a possible correlation between epidemiologic data and genotypic characteristics of M. canis isolated from dogs, cats and people. One hundred and two strains of M. canis isolated from symptomatic and asymptomatic dogs and cats and people with tinea between 2006 and 2010 were included in this study. These strains were from Curitiba, Porto Alegre, Florianópolis and Cuiaba. Among them, 37 were from symptomatic cats, 35 from asymptomatic cats, 19 from people with tinea, 9 from asymptomatic dogs and 2 from symptomatic dogs. Amplification of microsatellite DNA region was performed using two primers, McGT13 e McGT17, which allowed the formation of groups according to the degree of genetic similarity based on the amount of repetition in these two regions of M. canis DNA. Loci Mc(GT)13 e Mc(GT)17 revealed 3 and 6 alleles, varying between 2 and 5 dinucleotide repeats within each locus, respectively. Of the 14 genotypes and 5 major groups formed after phylogenetic tree analysis generated by DC method, 1 was shared by 26 strains, the other by 21, one by 12 strains and another two with 11 strains each. Microsatellite markers allowed identification, phylogenetic analysis and comparison of M. canis strains isolated from cats, dogs and people included in this study. Despite the formation of genetically related groups, there was no correlation between the lineage and epidemiologic characteristics, including source, symptoms, clinical picture, breed, age, sex, housing and geographical location.

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Furukawa-Stoffer, Tara Lee. "Characterization of triacylglycerol biosynthetic enzymes from microspore-derived cultures of oilseed rape." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0027/MQ38426.pdf.

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Furukawa-Stoffer, Tara L., and University of Lethbridge Faculty of Arts and Science. "Characterization of triacylglycerol biosynthetic enzymes from microspore-derived cultures of oilseed rape." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1996, 1996. http://hdl.handle.net/10133/63.

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Particulate and solubilized preparations of phosphatidate (PA) phosphatase (EC 3.1.3.4) and dia-cylglycerol acyltransferase (DGAT, EC 2.3.1.20) from microspore-derived (MD) cultures of Brassica napus L. cv Topas were characterized. The activity of solubilized PA phosphatase decreased by about 50% following storage for 24 h at 4 degrees celsius, whereas the activity of DGAT decreased by 30%. Bovine serum albumin increased the stability of both enzymes. Both preparations were enriched in the target enzyme and thus, may be useful in studies of regulation with limited influence by the other Kennedy pathway enzymes. Solubilized PA phosphatase was shown to dephosphoryolate a number of phosphate-containing compounds and showed a preference for dioleoyl-PA and dipalmitoyl-PA over other forms of PA tested. Microsomal PA phosphatase from MD embryos was partially dependent on Mg2+ and partially inhibited by the thioreactive agent, N-ethylmaleimide (NEM). The partial sensitivity to NEM suggest that MD embryos of B. napus may contain forms of PA phosphatase involved in glycerolipid synthesis and signal transduction. NEM-sensitive and NEM-insensitive PA phosphatase activity was found in microsomes of a cell suspension culture of B. napus L. cv Jet Neuf. PA phosphatase, solubilized from MD embryos, was partially purified using ammonium sulfate fractionation followed by anion exchange chromatography. PA phosphatase was resolved into two distinct peaks following anion-exchange chromatography. The peaks contained both NEM-sensitive and NEM-insensitive PA phosphatase activity. Following gel filtration, solubilized PA phosphatase displayed a minimum apparent Mr of about 40 000. Antibodies raised against partially purified preparations of PA phosphatase and DGAT from MD embryos of B. napus L. cv Topas were used in the development of immunochemical probes for these enzymes. Inhibitory anti-PA phosphatase antibodies were developed. Attempts were also made to identify a sub-class of antibodies which could interact with both denatured and native DGAT.
xviii, 137 leaves : ill. ; 28 cm.

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Shedden, John Douglas. "Transient expression of ß-glucuronidase in embryogenic Brassica napus microspores following particle bombardment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq20698.pdf.

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29

Zaki, Maged M. "The cell biology of haploid plant production from microspores of Brassica napus (L)." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292442.

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Correa, Fernanda Simas. "Avaliação da suscetibilidade a antifungicos de dermatofitos do genero Microsporum." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/308179.

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Orientador: Angelica Zaninelli Schreiber
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
Made available in DSpace on 2018-08-08T15:37:56Z (GMT). No. of bitstreams: 1 Correa_FernandaSimas_M.pdf: 2038543 bytes, checksum: 170a6e791e2c64d599b88b8485092a96 (MD5) Previous issue date: 2007
Resumo: Dermatófitos do gênero Microsporum acometem preferencialmente pele e pêlos, sendo M.canis e M.gypseum as espécies mais isoladas em nosso meio. Antifúngicos tópicos e sistêmicos são indicados para o tratamento destas dermatofitoses, que é considerado mais difícil quando comparado ao de outros gêneros de fungos queratinofílicos. Deste modo, a determinação da suscetibilidade aos antifúngicos in vitro destes microrganismos é de interesse para embasamento da terapêutica empírica, avaliação de falhas terapêuticas, e testes de novos antifúngicos. No entanto, os dermatófitos não foram incluídos no documento relacionado do CLSI (M38-A, 2002). Os estudos disponíveis até o momento, utilizando conídios dos fungos, apresentam resultados muito divergentes, devido a falta de padronização e o grande número de variáveis pré-analíticas envolvidas. Em adição, uma vez que a forma de hifas predomina no tecido infectado, há controvérsias sobre o fato de se a forma conidial seria adequada para os testes. Há poucos relatos na literatura sobre avaliação dinâmica de crescimento de fungos e a taxa de inibição destes por drogas antifúngicas, mas nenhum destes realizados com dermatófitos. Este estudo se propôs a determinar condições para realização do teste de suscetibilidade pelo método de microdiluição em caldo e padronizar a avaliação de crescimento dinâmico pelo sistema BCT® para seis cepas do gênero Microsporum, determinando respectivamente CIM e CFM e taxas de inibição de crescimento frente a ciclopirox olamina, terbinafina e griseofulvina. Os resultados obtidos apontaram: ágar batata como o melhor meio de cultura para produção de conídios, inóculo de 1x 103 células/ml, incubação de 7 dias a 28ºC e leitura final considerando 100% de inibição do crescimento para o teste de microdiluição em caldo. Os resultados de CIM variaram de 1,0 a 16,0 µg/ml para ciclopirox olamina, de 0,005 a 0,004 µg/ml para terbinafina e de 2,5 a 20,0 µg/ml para griseofulvina. No Sistema Automatizado BioCell-Tracer® os testes foram realizados com: concentração de PLL de 0,05%; inóculo ? 1x106 conídios/ml em 5?l; incubação a 30ºC por 72 a 96h; 30ºC como temperatura de realização do teste e tempo total de experimento de 3 horas e 30 minutos. Todas as cepas apresentaram taxa de inibição de crescimento acima de 85% na fase de exposição à droga frente aos antifúngicos avaliados, na concentração equivalente ao resultado de CIM obtido pela técnica de microdiluição em caldo e, em pelo menos, uma diluição abaixo
Abstract: Dermatophytes of the genus Microsporum preferentially invade skin and hair, being M.canis and M.gypseum the most prevalent species in our routine. Topics and systemic antifungal agents are indicated for the treatment of theses dermatophytoses, which is considered more difficult when compared to other genera of keratinofilic fungi. By the way, the determination of in vitro antifungal susceptibility of these organisms is interesting as a guide of empiric therapy, evaluation of therapeutic failures and to evaluate new antifungal agents. However, dermatophytes were not included in the CLSI document (M38-A, 2002). The studies available until now, using fungi conidia, present divergent results due to the lack of standartization and the large number of pre-analytical variables involved. In addiction, once the hyphae forms predominate in infected tissues, there are controversies about if the conidial form would be adequate for the tests. There are few articles in the literature about dynamical evaluation of fungi growth and their growth inhibition rate in contact with antifungal agents, but none with dermatophytes. This study proposed the determination of conditions for broth microdilution susceptibility test and the standardization of dynamical growth evaluation by the BCT® system for six strains of Microsporum sp, determining respectively MIC and MFC and the inhibition rate after application of ciclopirox olamine, terbinafine and griseofulvin. The results pointed: potato dextrose agar as the best culture medium for conidium production, inoculum concentration of 1x 103 conidia/ml, incubation for 7 days at 28ºC and test enpoint at 100% of growth inhibition for broth microdilution test. The MIC results ranged from 1,0 to16,0 µg/ml for ciclopirox olamine, 0,005 to 0,004 µg/ml for terbinafine and 2,5 to 20,0 µg/ml for griseofulvin. On the automatizated system BioCell-Tracer®, the tests were realized with: PLL concentration of 0,05%; inocula of ? 1x106 conídia/ml in 5?l; incubation at 30ºC for 72 to 96hand also 30ºC as the test temperature, 3 hours and 30 minutes as total time of experiment. All strains showed growth inhibition rate above 85% on drug exposure phase against the antifungal agents evaluated, in MIC obtained by both microdilution method and, at least, one dilution below
Mestrado
Patologia Clinica
Mestre em Ciências Médicas

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Ferreiro, Laerte. "Étiopathogénie des infections à Microsporum canis : étude d'une éxoprotéase kératinolytique." Paris 12, 1995. http://www.theses.fr/1995PA120039.

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Microsporum canis est le principal agent de dermatophytose chez les carnivores domestiques et est a l'origine d'infections zoonotiques tres frequentes dans le monde entier. Pour mieux comprendre les interactions hote-parasite, il est necessaire d'etudier les differents composants des champignons pouvant intervenir dans leur pathogenicite ainsi que les mecanismes de defense de l'hote, en particulier, la reponse immune. Ainsi pour etudier l'infection a m. Canis chez les carnivores domestiques, nous avons, dans un premier temps, isole de nombreuses souches de m. Canis chez des carnivores domestiques. Ensuite nous avons compare leurs profils electrophoretiques et leurs activites enzymatiques. Dans toutes ces souches, nous avons decele une activite keratinasique ; en outre, les souches exprimant une forte activite chymotrypsique provenaient des lesions les plus inflammatoires. Parallelement, nous avons teste un modele experimental d'infection par microsporum canis chez le chat notamment avec un inoculum forme d'arthroconidies produites in vitro. Ensuite, afin d'etudier les keratinases de m. Canis, nous avons selectionne les souches les plus productives et optimise les conditions de culture. Une keratinase a ete caracterisee comme etant une serine-protease de type chymotrypsique/substilisine avec un ph optimal de 8,5. La purification de cette protease par chromatographie d'affinite sur phenylalanine-agarose suivie d'une analyse en sds-page nous a permis d'estimer sa masse moleculaire a 33 kda. Enfin, nous avons etudie l'immunite humorale chez des carnivores naturellement et experimentalement infectes par m. Canis par electrosynerese et par immuno-empreinte (western blot). Des anticorps anti-m. Canis ont ete detectes chez 24% des animaux infectes par m. Canis, mais plus frequemment chez les chiens infectes (65%) que chez les chats (13%). Nous avons montre que cette reponse humorale etait dirigee contre de nombreux antigenes de m. Canis ; en revanche la recherche d'anticorps anti-chymotrypsine de m. Canis s'est revele negative

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Tratt, Julia. "Identifying the wall-degrading enzymes responsible for microspore release from the pollen tetrad." Thesis, University of Bath, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.687381.

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Dissolution of the pollen tetrad walls after meiosis, and subsequent release of the haploid microspores, is essential for pollen development in many species, including Arabidopsis thaliana. The thick wall of the tetrad consists of callose (β-1,3-glucan), with a primary cell wall of cellulose, hemicellulose and pectin surrounding the whole structure. Despite the importance of microspore release, not all the wall-degrading enzymes involved have been identified in A. thaliana. 18 endo-β-1,3-glucanase genes were identified in A. thaliana that are expressed in buds at microspore release. Single and multiple-gene T-DNA insertion lines showed no detectable phenotype, indicating possible gene redundancy. GFP-tagging of the two most specifically expressed genes (AtA6 and AtA6F) showed AtA6 is present in the locule at microspore release, but AtA6F is not. Early ectopic expression of AtA6 and AtA6F showed they have enzymatic activity, but may not be able to directly target the callose wall of the tetrad. Although endo-β-1,3-glucanases are likely to be most important for callose degradation, there are exo-β-1,3-glucanase encoding genes expressed at microspore release. Two GH3 exo-β-1,3-glucosidases are highly expressed at microspore release and so may play a role in tetrad dissolution. However, the GH5-14 exo-β-1,3-glucosidases found in most plant species are absent from A. thaliana and all other sequenced members of the Brassicales. Three genes (named the ‘QUARTET’ genes) are important for degradation of the pectin component of the outer wall. Here, analysis of double and triple quartet T-DNA insertion lines indicated redundancy between the QRT genes. Degradation of only the pectin component of the wall may be sufficient for microspore release, however, six endo-β-1,4-glucanase genes are expressed in the anther at microspore release, and may target cellulose or hemicellulose in the tetrad cell wall. T-DNA insertion line analysis showed no phenotypic differences compared to wild-type, indicating that these endo- β-1,4-glucanases may not play a major role in microspore release.

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Policarpo, Lucas Makrakis. "Estudo de equilíbrio e cinética da biossorção de cobre (II) por Rhizopus Microsporus." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-13072016-162516/.

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A poluição relacionada a metais pesados tem recebido uma atenção especial devido a sua alta toxicidade, não biodegradabilidade e tendência de acumular-se na cadeia alimentar. Apesar disso, metais pesados também são considerados recursos valiosos, portanto a sua remoção em conjunto com a sua recuperação torna-se ainda mais importante. Este caso aplica-se aos rejeitos de mineração de cobre, os quais oferecem a possibilidade de recuperação do metal e de sua contenção de maneira segura do meio ambiente. Tais rejeitos se caracterizam por ocuparem enormes áreas inundadas e abrigarem soluções diluídas de cobre (II), porém, muitas vezes, acima dos limites seguros. Diversos processos tradicionais de tratamento mostram-se disponíveis para remover o cobre de tais soluções, no entanto, em certas aplicações eles podem ser ineficientes ou muito onerosos. Nesse contexto, a biossorção é uma alternativa interessante. Nesse processo, certos microrganismos, como fungos, bactérias e algas, ligam-se passivamente ao cobre na forma íons ou outras moléculas em soluções. No presente trabalho foi avaliado o potencial de biossorção de íons cobre (II) pela biomassa do fungo Rhizopus microsporus, coletado e isolado da área de rejeitos da Mina do Sossego, na região norte do Brasil. Isotermas de biossorção foram determinadas experimentalmente em bateladas sob temperatura de 25°C, agitação de 150 rpm, concentração de biomassa de 2,0 a 2,5 g/L e tempo de contato mínimo de 4 horas. O pH mostrou ser um fator importante no equilíbrio da biossorção, sendo o valor máximo da capacidade de biossorção de 33,12 mg de cobre / g biomassa encontrado em pH 6. Valores sucessivamente menores são encontrados pela acidificação da solução, sendo o pH 1 considerado adequado para o processo de dessorção, correspondendo a uma capacidade de biossorção de 1,95 mg/g. Modelos de adsorção de Langmuir e de Freundlich ajustaram-se adequadamente às isotermas tanto com pH controlado quanto não controlado. Foi constatado que a troca iônica é um dos mecanismos envolvidos na biossorção do cobre com Rhizopus microsporus. Tanto o modelo de pseudo-primeira ordem quanto o de pseudo-segunda ordem ajustaram-se aos dados cinéticos da biossorção, sendo que o equilíbrio ocorre em aproximadamente 4 horas. A biomassa conservou a capacidade de biossorção ao operar repetidamente em três ciclos de sorção-dessorção. A biomassa viável e a morta não apresentaram diferença estatisticamente significativa na capacidade de biossorção.
Heavy metal pollution has been receiving a special attention because of the high toxicity of these metals, by their non-biodegradability and by their tendency to accumulate throughout the food chain. Nevertheless, heavy metals are also considered valuable resources, hence their recovery and recycle assumes even greater significance. This is the case of copper mining tailings, which offer the possibility of metal recovery while it must be safely contained from the environment. These wastes are characterized by occupying huge flooded areas with very dilute copper (II) solutions, however, in many cases above safe limits. Various traditional treatment methods are available to remove copper from such solutions; however, for certain applications they may be either ineffective or too costly. In this context, biosorption becomes an interesting alternative. In this process, certain microorganisms such as fungi, bacteria and algae, passively bind to the copper ion or other molecules in solution. In the present study the biosorption potential of copper (II) by the fungal biomass of Rhizopus microsporus, collected and isolated from the tailings area of Sossego mine, located in the northern region of Brazil, has been evaluated. Biosorption isotherms have been experimentally determined by batch experiments at a temperature of 25C, agitation speed of 150 rpm, biosorbent concentration in the range of 2.0 to 2.5 mg/L, and contact time of at least 4 hours. The pH has been found to be a determining factor for the sorption equilibrium, a maximum sorption capacity of 33.12 mg copper / g biomass being found at pH 6. Successively smaller values have been found by the acidification of the solution. A pH value of 1 has been considered adequate for the desorption process, which correspond to a biosorption capacity of 1,95 mg/g. Both Langmuir and Freundlich adsorption models fitted well to equilibrium data using both pH methodologies, however the determination coefficient is slightly higher for the former model. It has been found that ion exchange is one of the mechanisms involved in copper (II) biosorption by Rhizopus microsporus. Both pseudo-first and pseudo-second order models have fitted well to biosorption kinetic data. Equilibrium approaches within approximately 4 hours. The biosorbent has proved to maintain its sorption efficiency after three regeneration cycles. Viable and dead biomasses have not exhibited statistically significant difference in sorption behavior.

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LEAL, Carlos Adriano de Santana. "Desenvolvimento de uma multiplex PCR para identificação das principais espécies de dermatófitos que acometem cães e gatos." Universidade Federal Rural de Pernambuco, 2017. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/7303.

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The aim of this study was to standardize a multiplex PCR (mPCR) reaction to detect Microsporum canis, Microsporum gypseum and the Trichophyton mentagrophytes complex in fur and/or crusts samples of dogs and cats. 250 samples were analyzed by direct examination and culture; The DNA from these samples was extracted using the DNeasy Blood & Tissue extraction kit (QIAGEN®, Hilden-Germany). For the PCR, primers were designed for the M. canis, M. gypseum and T. mentagrophytes species and the DNA extracted from colonies of M. canis (URM 6273), M. gypseum (URM 6921) and T. mentagrophytes (URM 6211) from the Collection of Cultures of the Micoteca of the Mycology Department of the Biological Sciences Center of the Federal University of Pernambuco, were utilized as positive controls. A PCR for the detection of M. canis and an mPCR for the detection of M. canis, M. gypseum and the T. mentagrophytes complex was standardized. The protocols standardized in this study, from drawn primers, showed good sensitivity and high specificity in the detection of M. canis, M. gypseum and T. mentagrophytes directly from samples of fur and/or crusts of dogs and cats, making possible a faster and specificity in the results, can be used in the laboratory routine as methods capable of speeding the detection of the agents in question.
Objetivou-se neste estudo padronizar uma reação do tipo multiplex PCR (mPCR) para detectar Microsporum canis, Microsporum gypseum e o complexo Trichophyton mentagrophytes em amostras de pelos e/ou crostas de cães e gatos. Foram analisadas 250 amostras por meio de exame direto e cultura; o DNA destas mesmas amostras foi extraído utilizando-se o kit de extração DNeasy Blood & Tissue (QIAGEN®, Hilden - Germany). Para a PCR foram desenhados primers para as espécies M. canis, M. gypseum e T. mentagrophytes e como controle positivo da reação utilizou-se o DNA extraído de colônias de M. canis (URM 6273), M. gypseum (URM 6921) e T. mentagrophytes (URM 6211), provenientes da Coleção de Culturas da Micoteca do Departamento de Micologia do Centro de Ciências Biológicas da Universidade Federal de Pernambuco. Padronizou-se uma PCR para detecção de M. canis e uma mPCR para detecção de M. canis, M. gypseum e o complexo T. mentagrophytes. Os protocolos padronizados neste estudo, a partir de primers desenhados, apresentaram boa sensibilidade e alta especificidade na detecção de M. canis, M. gypseum e T. mentagrophytes diretamente de amostras de pelos e/ou crostas de cães e gatos, viabilizando um diagnóstico mais rápido e específico, podendo ser empregados na rotina laboratorial como métodos para agilizar a detecção dos agentes estudados.

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Maria, Rodrigues de Barros Corrêa Damázio Paula. "Dermatofitoses no Estado de Pernambuco : perfil epidemiológico e série de casos." Universidade Federal de Pernambuco, 2006. https://repositorio.ufpe.br/handle/123456789/7457.

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Introdução: As dermatofitoses são infecções fúngicas freqüentes entre os homens. A constante mudança do perfil epidemiológico tornam necessários estudos regulares. O objetivo deste trabalho é determinar as dermatofitoses mais comuns em Pernambuco e seus agentes. Material e Métodos: Estudo transversal utilizando os registros de pacientes atendidos no Laboratório de Micologia Médica da Universidade Federal de Pernambuco durante o período de janeiro de 1995 a julho de 2005. Resultados: Foram analisados 1238 casos de dermatofitoses de 1105 pacientes. Os homens somaram 51,76% dos pacientes e os menores de 21 anos 51%. Trichophyton tonsurans e T. rubrum foram as espécies mais isoladas na primeira e segunda metades do estudo, respectivamente. Conclusão: Não houve diferença significativa entre os sexos nas tinhas em geral, as quais foram mais prevalentes em menores de 21 anos. A tinha de pele glabra e T. rubrum são, atualmente, a forma clínica e dermatófito mais freqüentes em Pernambuco

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Nehlin, Lilian. "The use of rapeseed (Brassica napus L.) microspores as a tool for biotechnological applications /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5490-5.pdf.

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Zhong, Danni. "Culture "in vitro" d'anthères et de microspores isolées de tournesol cultivé (Helianthus annuus L. )." Montpellier 2, 1992. http://www.theses.fr/1992MON20265.

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Deux methodes d'androgenese ont ete etudiees chez le tournesol cultive: culture in vitro d'antheres et de microspores isolees. Dans la culture in vitro d'antheres, l'incorporation du pvp insoluble ou de la cysteine a permis d'ameliorer le potentiel embryogene des antheres. Une relation inverse entre le brunissement enzymatique et les activites ppo et po d'un cote et le potentiel embryogene de l'autre a ete etablie. Les transferts successifs des embryons obtenus sur le milieu de regeneration contenant du saccharose en concentrations decroissantes a permis d'augmenter de facon significative le pourcentage de plantes regenerees. Les etudes histologiques ont demontre que les embryons obtenus ont essentiellement une origine somatique. Dans la culture de microspores isolees, les processus d'isolement et de purification ont ete mis au point. Des poils pluricellulaires, obtenus lors du broyage des antheres peuvent se diviser et donner des cals et representent donc une reactivite parasite lors de la culture des microspores. Dans les meilleures conditions actuelles, apres 3 semaines de culture, 0,3 a 0,5% des microspores peuvent se diviser et se developper jusqu'a un stade de proembryon

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Lemonnier--Le, Penhuizic Claire. "Effets d'oligosaccharides sur l'embryogenèse de microspores de brocoli : : mode d'action et transduction du signal." Rennes 1, 2001. http://www.theses.fr/2001REN10085.

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L'induction embryogène dans des cultures de microspores isolées est un processus dépendant d'un stress, qui peut être déclenché par un choc thermique, une privation de saccharose ou de nitrogène ou par l'utilisation d'inhibiteurs de la polymérisation des microtubules. Connus pour mimer des stress biotiques, les oligosaccharides ont été testés en tant que source de composés inducteurs de l'embryogenèse de microspores de Brassica napus var. Italica. Parmi les huit séries d'oligosaccharides étudiés et leurs polymères respectifs (à savoir des pectines, des alginates, des fucanes, des laminarines, des agars et des ?-, ?-, ?-carraghénanes) seuls les oligo-carraghénanes présentaient des effets significatifs sur l'induction des microspores. Ajoutés en combinaison avec un choc thermique, ils augmentaient très fortement les rendements finaux en embryons dérivés de microspores. Ainsi, un doublement du rendement était observé dans le cas du traitement le plus efficace, c'est-à-dire en présence d'oligo-?-carraghénanes. Le mode d'action des oligo-carraghénanes a été étudié en suivant le devenir d'oligosaccharides fluorescents. Les oligo-carraghénanes peuvent entrer dans les cellules ; toutefois, l'utilisation d'oligo-carraghénanes biotinylés immobilisés sur des billes de streptavidine a révélé que les molécules exerçaient probablement leurs effets au niveau extracellulaire. Les réponses ont été comparées avec celles obtenues lors de traitements avec des peptides contenant la séquence RGD (site de reconnaissance universel des molécules d'adhésion des cellules animales) sur des cultures de microspores. Les traitements à l'aide de peptides RGD présentaient des résultats similaires sur l'induction de l'androgenèse et semblaient entrer en compétition avec les sites de liaisons des oligo-carraghénanes. Des études pharmacologiques ont permis de montrer que la signalisation des oligo-carraghénanes et des peptides RGD présentent des voies de transduction communes, impliquant des protéines kinases et des MAP kinases, éléments distincts de la voie de transduction du choc thermique. Ces données ont permis de proposer un modèle hypothétique de l'induction de l'embryogenèse par modification de la polarité des microspores. Le développement propre des grains de pollen nécessite une adhésion polarisée pour établir de possibles connections au niveau cortical. . .

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Kocsis, Michael G., and University of Lethbridge Faculty of Arts and Science. "Characteristics of phosphatidate phosphatase from developing seeds and microspore-derived cultures of oilseed rape." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1994, 1994. http://hdl.handle.net/10133/23.

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Phosphatidate phosphatase (PAP. EC 3.1.3.4) was charaterized from developing seeds and microspore-derived (MD) cultures of oilseed rape. In studies with homogenate from developing seeds (Brassica napus L. cv Westar) the time course for release of inorganic phosphate from phosphatidate was linear for at least 60 min and the enzyme was stable to at least three cycles of freezing and thawing. Differential centrifugation studies were conducted with homogenate prepared from developing seeds (B. napus L. cv Westar), MD embryos (B. napus L. cv Reston), and an embryogenic MD cell suspension culture (B. napus L. cv Jet Neuf). Among the three tissue types, the level of microsomal PAP ranged from 11% to 17% of the total recovered PAP activity whereas soluble PAP ranged from 25% to 61% of the total activity recovered. Microsomal PAP displayed optimal activity in the pH range of 6 to 7 whereas soluble PAP had a pH optimum of 5. Microsomal and soluble PAP exhibited temperature reaction optima of 40 degrees celsius and 50 degrees celsius, respectively, with activation energies of 15.6 kcal/mol and 9.4 kcal/mol. Assays with p-nitrophenyl phosphate as a substrate at pH 6.75 and pH 5 indicated that the overal character of phosphatase activity in the microsomal fraction was different from the enzyme in the soluble microsomal PAP from MD embryos of B. napus L. cv Topas. Tween 20 solubilized PAP effectively with concomitant maintenance of enzyme in the soluble fraction. A number of detergents were screened for their ability to solubilize microsomal PAP from MD embryos of B. napus L. cv Topas. Tween 20 solubilized PAP effectively with concomitant maintenance of enzyme activity. The most effective solubilization of enzyme occurred at a concentration of 0.4% (w/v) Tween 20 at a detergent to protein ratio of 1:1 (w/w). The pH optimum (pH 6-7) of solubilized PAP was similar to that of the particulate enzyme and the assay of the solubilized enzyme was free from interference by phospholipase action. Solubilized microsomal PAP had an apparent Mr of about 300,000 based on gel filtration chromatography on a column of Superose 6. Polyclonal antibodies raised in mice against a crude extract from microsomes of MD embryos inhibited microsomal PAP activity.
xii, 128 leaves : ill. ; 29 cm.

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Giudice, Mauro Cintra. "Avaliação das atividades enzimáticas (queratinase e elastase) e biotipagem molecular de amostras de Microsporum gypseum isolados de diferentes fontes e regiões geográficas do Brasil." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-30032009-165027/.

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Estudou-se Microsporum gypseum de diferentes fontes regiões geográficas do Brasil.Os fungos foram isolados do solo, de animais e obtidos em coleções de cultura. Em 692 amostras de solo e a taxa de recuperação foi de 19,2%. A atividade queratinolítica e elastinolítica foi avaliada quantitativamente em 138 amostras de M. gypseum. A biotipagem molecular foi realizado através da técnica de PCR-RFLP com a enzima MvaI. O seqüenciamento da região ITS1 do rDNA foi realizado em amostras representativas. M. gypseum de amostras clínicas e do solo mostraram diferenças quantitativas significantes na expressão das enzimas. A PCR-RFLP para a região ITS1 não mostrou diferença. Pelo seqüenciamento foram obtidas duas espécies sexuadas (A. gypseum e A. incurvatum). As atividades enzimáticas sugerem um importante papel na patogenicidade e uma provável adaptação desta espécie de fungo ao parasitismo animal. A análise dos resultados pode auxiliar a identificação e o conhecimento de mecanismos de virulência destes fungos.
Microsporum gypseum from different geographical sources and regions of Brazil were studied. The fungi were isolated from the soil, animals and obtained in collections of culture. In 692 samples of soil, the recovery rate was 19.2%. The keratinolytic and elastinolytic activities were quantitatively performed on 138 samples of M. gypseum. The molecular biotyping was carried out by the technique of PCR-RFLP with the enzyme MvaI. The sequencing of the region ITS1 rDNA was carried out on representative samples. Samples of M. gypseum from clinical isolates and from soil showed significant quantitative differences in the expression of enzymes. The PCR-RFLP for the ITS1 region showed no difference. For the sequencing was obtained two sexual species (A. gypseum and A. incurvatum). The enzyme activities suggest an important role in pathogenicity and a likely adjustment of this kind of parasitic fungus to feed. The results may help the identification and knowledge of mechanisms of virulence of these fungi.

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Esteves, Patricio. "Optimisation de la culture de microspores isolées chez les orges de printemps à six rangs." Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30476/30476.pdf.

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Les plantes haploïdes doublées (HD) sont des individus complètement homozygotes qui peuvent être obtenus via l’androgenèse in vitro. Les HD sont très appréciés comme outils de recherche en génétique et en amélioration végétale. La culture de microspores isolées (CMI) est le moyen le plus efficace de produire des HD. Malheureusement, les orges de printemps à six rangs, le type prédominant cultivé dans l’Est du Canada, sont considérées comme récalcitrantes à cause d’une faible embryogenèse et d’une propension à l’albinisme. Notre objectif était de développer un protocole CMI adapté à ce type d’orge. Nous avons entamé des travaux exploratoires sur quatre cultivars : ACCA et Léger (six rangs, printemps), Gobernadora (deux rangs, printemps) et Igri (deux rangs, hiver). Dans une première phase, nous avons évalué l’impact de quatre facteurs physiques. Nous avons trouvé que l’optimisation du stade de récolte des tiges pouvait augmenter de 2 à 4 fois la récolte de microspores embryogéniques. Deuxièmement, deux des prétraitements (0,3 M mannitol pendant 2 jours et une combinaison de froid et de chaleur pendant 15 jours) ont tous deux été significativement plus productifs qu’un prétraitement très largement employé (28 jours à 4 °C). Troisièmement, l’ajout de mannitol au milieu d’induction a permis de doubler le nombre de plantes vertes obtenues. Finalement, la densité des microspores à l’étalement a eu un impact significatif sur l’obtention de plantes vertes, 106 microspores/ml s’étant avéré optimal. Dans une deuxième phase, nous avons exploré l’utilisation de régulateurs de croissance alternatifs tant dans le milieu d’induction (thidiazuron et dicamba) que de régénération (meta-topoline). Comparativement à des milieux témoins contenant principalement la 6-benzyl-aminopurine, nos milieux d’induction ont produit 5,1 fois plus de plantes vertes, principalement par réduction de l’albinisme. Notre milieu de régénération amélioré a permis d’obtenir 2,9 fois plus de plantes vertes que le témoin. Finalement, ces résultats ont été validés avec succès sur des génotypes F1 d’un programme d’amélioration. Au terme de ce travail, nous avons ainsi réussi à améliorer substantiellement l’efficacité de la CMI chez les orges de printemps à six rangs.
Doubled haploid (DH) plants are completely homozygous individuals that can be generated via in vitro androgenesis. DHs are useful as research tools both for genetic studies and in plant breeding. Isolated microspore culture (IMC) is the most efficient way to produce DHs. Unfortunately, six-row spring barley genotypes, the main type produced in Eastern Canada, are considered recalcitrant because of a low embryogenesis and a high rate of albinism. Our objective was to develop an IMC protocol more suitable to this type of barley. We carried out exploratory work on four barley cultivars: ACCA and Léger (six-row, spring), Gobernadora (two-row, spring) and Igri (two-row, winter). In a first phase, we explored four factors. First, we found that a 2-4-fold increase in the yield of embryogenic microspores is possible by optimizing the harvest stage for each genotype. Second, two pretreatments (0.3M mannitol for 2 days or a combination of cold and heat over 15 days) both performed significantly better than the commonly used cold pretreatment (28 days at 4°C). Third, an induction medium containing mannitol doubled green plant regeneration. Fourth, we observed a marked effect of microspore plating density on the number of green plants obtained, with 106 microspores/ml yielding the best results. In a second phase we explored the use of alternative growth regulators both in the induction medium (thidiazuron and dicamba) and in the regeneration medium (meta-topoline). Compared to control media containing 6-benzyl-aminopurine, our improved induction medium lead to a 5.1-fold increase in green plant production, mainly achieved by reducing albinism. Similarly, our regeneration medium yielded 2.9-fold more green plants than the control. Finally, these results were successfully validated using F1 genotypes from a breeding program. On the whole, we have succeeded in substantially improving the efficiency of IMC in this type of recalcitrant barley.

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Maglione, Rémi. "Étude de l'intégrité du génome chloroplastique de l'orge (Hordeum vulgare) en culture de microspores isolées." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/26919.

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Un enjeu actuel en biotechnologie est d'obtenir des plantes haploïdes doublées par la technique de la culture de microspores isolées (CMI). Pourtant, la CMI génère parfois une proportion importante de plantes albinos, laquelle peut atteindre 100 % chez certains cultivars. Des travaux antérieurs ont indiqué que des remaniements du génome chloroplastique seraient à l'origine de cet albinisme. Afin de mieux comprendre ce processus menant à l'albinisme, nous avons entrepris d'étudier l'intégrité du génome chloroplastique au sein de microspores d'orge et de plantes albinos via une approche de séquençage à grande échelle. L'ADN total extrait de microspores à un stade précoce de la CMI, d'une feuille de la plante-mère (témoin), et de feuilles albinos, a été séquencé et les séquences chloroplastiques ont été analysées. Ceci nous a permis de documenter pour la première fois une diminution de l'ADN chloroplastique chez les microspores. De plus une étude de variations structurales a démontré un abaissement généralisé de la quantité de génomes chloroplastiques chez les microspores. Enfin, d'importants remaniements du génome chloroplastique ont été observés chez les plantes albinos, révélant une forte abondance de génomes chloroplastiques altérés de forme linéaire.

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Cholley-Vignardet, Céline. "Approche de la connaissance d'une nouvelle keratinase de doratomyces microsporus (sacc. ) morton et smith par des etudes physico-chimiques et la recherche d'applications sur differents substrats keratinises (doctorat : sciences pharmaceutiques)." Besançon, 1999. http://www.theses.fr/1999BESA3511.

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Byers, Susan D. "Stimulation of microsomal diacylglycerol acyltransferase activity from microspore-derived cell suspension cultures of oilseed rape." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0016/MQ49143.pdf.

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Byers, Susan D., and University of Lethbridge Faculty of Arts and Science. "Stimulation of microsomal diacylglycerol acyltransferase activity from microspore-derived cell suspension cultures of oilseed rape." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1999, 1999. http://hdl.handle.net/10133/101.

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Several factors including an unidentified endogenous substance were found to stimulate microsomal diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) from a microspore-derived cell suspension culture of oilseed rape (Brassica napus L. cv Jet Neuf). Mg2+ salts were found to stimulate microsomal DGAT 14 to 23-fold. ATP and CoA were also found to stimulate the enzyme 2.4 and 12 fold respectively, although the effects were decreased in the presence of high Mg2+ concentrations. While microsomal DGAT activity was only slightly increased by the concentration of exogenous diacylglycerol in the reaction mixture it was increased substantially by the addition of exogenous phosphatidate. Other phospholipids tested were not found to have this stimulatory effect. During attempts to investigate possible covalent modification of the enzyme, the soluble fraction obtained from cell suspension homogenate was found to contain a small metastable organic molecule(s) which stimulated DGAT activity. Stimulation of microsomal DGAT by this factor was concentration dependent but not dependent on preincubation time.
xiii, 95 leaves : ill. ; 28 cm.

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46

MOHAMED, ABDELGALEL MOHAMED Ahmed. "STUDY ON GAMETIC EMBRYOGENESIS VIA IN VITRO ANTHER AND ISOLATED MICROSPORE CULTURE IN FRUIT CROPS." Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/91257.

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Fruit breeding is mainly based on both conventional (hybridization, mutation and selection) or biotechnological methods (somatic hybridization, genetic transformation and haploid production). The genetic improvement through the conventional methods is limited by many factors such as fruit trees long juvenile period, high heterozygosity, large size and sexual incompatibility. Haploids and doubled haploids, obtained through gametic embryogenesis have a potential use in fruit crops genetic improvement. The change of the microspores fate from the normal gametopytic pathway towards the sporophytic induction is affected by numerous factors. Genotype, medium composition and stress were considered the most important factors required to switch the pollen embryogenic development. During this doctoral course, researches have been carried out on gametic embryogenesis in different fruit crops via anther and isolated microspore culture. Particularly, for the first time, embryos were obtained by isolated microspore culture technique in Citrus spp. Morover, somatic embryogenesis callus and regeneration of plantlets were achieved via anther culture in blood sweet oranges, C. sinensis L. Osbeck, cvs. Moro, Tarocco Meli, Tarocco TDV and Tarocco S. Alfio, homozygous callus, embryos and plantlets were instead obtained from Citrus clementina Hort. ex Tan. cvs. Hernandina and Corsica. These results represent an advancement of plant breeding and propagation techniques in Citrus spp. Research has been also carried out on Olea europaea L. gametic embryogenesis, multicellular structures have been obtained from anther and isolated microspore culture, as the first step towards haploid olive embryos production. Furthermore, a preliminary experiment has been carried out on of several hazelnut (Corylus avellana L.) cultivars to obtain regeneration through anther and isolated microspore culture.

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Sparkes, Andrew Howard. "Aspects of feline dermatophytosis and the immune response to Microsporum canis infection." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385524.

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CRAMBES, ELISABETH. "Obtention de plantes androgenetiques chlorophylliennes issues de microspores isolees chez le ble tendre (triticum aestivum l. )." Université Louis Pasteur (Strasbourg) (1971-2008), 1995. http://www.theses.fr/1995STR13250.

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Le but de cette these etait de mettre au point une methodologie permettant d'obtenir a partir de microspores initialement isolees de ble tendre des embryons androgenetiques puis des plantes chlorophylliennes. Apres une etude bibliographique des differents travaux menes sur l'amelioration de la culture d'antheres et son evolution vers la methode de culture de microspores isolees chez differentes especes, nous mettons en evidence les interets du modele microspores isolees mais aussi les difficultes rencontrees par les differents laboratoires pour en etablir la reproductibilite. Les travaux sont realises sur deux genotypes de printemps (wim et hd112) connus pour leurs bonnes aptitudes a l'androgenese et utilises comme temoins et quatre genotypes d'hiver v2, a, b et c selectionnes par les selectionneurs pour leurs interets economiques. Les microspores sont obtenues apres un protocole d'extraction simplifie de broyage, filtration et centrifugation et mises en culture sur le milieu liquide de chu. L'augmentation de la concentration molaire de sucre a 0,26m et la coculture des microspores avec des ovaires de ble a permis l'induction de l'embryogenese et l'obtention de plantes chlorophylliennes. Ainsi, pour le meilleur genotype (hd112), 0,5% des microspores sont induites et 1& regenerent une plante chlorophyllienne. Nous avons alors mene une etude comparative entre la culture de microspores isolees et la culture d'antheres dont les rendements ont par ailleurs ete ameliores au cours de cette these. Le developpement des embryons en plantes vertes est identique entre les deux methodes. Par contre, l'analyse du niveau de ploidie montre une preponderance de la frequence des plantes haploides en culture de microspores isolees (90 a 100%) qu'en culture d'antheres (43,7 a 79,5%). Les ameliorations de ce systeme et les perspectives qu'offre une telle culture, notamment dans le domaine de la transformation genetique, sont discutees a la fin de cette these

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Davoren, Jonathan M., and University of Lethbridge Faculty of Arts and Science. "Gene expression in a microspore-derived cell suspension culture of Brassica Napus exhibiting enhanced oil production." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1997, 1997. http://hdl.handle.net/10133/345.

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Triacylglycerol (TAG) production in the microspore derived (MD) cell suspension culture ofBrassica napus L. cv Jet Neuf was enhanced when the sucrose concentration in the growth medium was increased from 2 to 14 % (w/v). mRNA differential display by polymerase chain reaction was used to examine gene expression in cells grown at different sucrose concentrations in order to identify mRNAs which could be associated with oil formation. The anchored primer, T12AA, was used to screen one subset, representing approximately one twelfth of the transcript population, isolated from cultures grown in media supplemented to 2, 6 and 14 % (w/v) sucrose. Analysis of this mRNA subset revealed thirteen cDNAs which appeared to be upregulated as the sucrose concentration was increased. Cloning and sequencing revealed multiple cDNA fragments for each signal detected by differential display. RT-PCR analysis of sixteen different cDNAs revealed that eight encoded mRNAs which were upregulated in parallel to the increase in media sucrose. Comparison of the eight upregulated cDNAs to other sequences in GenBank revealed the following: (1) BSS8A had a 100% identity with the last 25 amino acids of an acyl carrier protein from Arabidopsis thaliana, (2) BSS1A displayed homology to a number of sequences of unknown function, (3) BSS1 IB displayed weak but significant homology to a number of sequences of unknown function, (4) BSS13A displayed homology to four members of the thioredoxin family from ,4. thaliana and (5) four Had no significant homology to previously reported sequences which makes them potential candidates to encode lipogenic enzymes. These results indicate that differential display of mRNA may be a simple and rapid method for the identification of sucrose-modulated gene expression changes in this system and for the characterization of novel sequences potentially encoding lipogenic proteins.
xxi, 256 leaves : ill. ; 28 cm.

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Branco, Junior Armando Castello. "Estudos ecologicos e patologicos da infecção por Polidispyrenia simulu (Microspora : Pleistophoridae) em uma comunidade de Simulideos." [s.n.], 1991. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315815.

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Orientador : Carlos Fernando S. de Andrade
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-07-14T00:21:30Z (GMT). No. of bitstreams: 1 BrancoJunior_ArmandoCastello_M.pdf: 5894643 bytes, checksum: 115de0a11659e19ead484b0be8a5b106 (MD5) Previous issue date: 1991
Resumo: No presente trabalho foi avaliada a ocorrência natural da microsporidiose causada por Polidispyrenia simulii em uma comunidade de simulídeos composta por três espécies, Simulium pertinax, S. subpallidum e S. pruinosum, em um riacho pertencente à bacia do rio Jaguari, no município de Morungaba, SP. Os resultados obtidos a partir de amostragens periódicas de larvas ao longo de um ano revelaram que as três espécies de simulídeos são susceptíveis à P. simulii, sendo que este ocorre em freqüentes epizootias nas populações larvais de S. pertinax e S. subpallidum, enquanto sua presença em S. pruinosum foi detectada muito raramente. As freqüências de infecção em larvas pequenas, médias e grandes indicam que larvas pequnas são mais afetadas pela doença. Além das freqüências de infecção diferenciadas nas três classes de tamanho, a ausência da infecção em pupas e adultos originados de indivíduos infectados indicam que a manutenção da doença no campo deve-se em grande parte a um mecanismo de transmissão horizontal. Estudos de laboratório revelaram que a infecção por P. simulii provoca o fenômeno de metatetelia nos indivíduos doentes, além de alterações nas respostas comportamentais destas. Estas alterações provavelmente comprometem a capacidade de competição por substrato para fixação e sítios de alimentação, além de aumentar a susceptibilidade dos indivíduos infectados a outros inimigos naturais, como predadores e parasitas...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: The present work was undertaken to investigate natural occurence of Polidispyrenia simulii (Microspora, Pleistophoridae) in larvae populations of blackfly and to study ecological and pathological aspects of the pathogen-host relation. This work undertaken under field and laboratory conditions. Field work was done with Simulium pertinax, S. Subpallidum a S. Posum larvae while laboratory work was done with larvae, pupae and adults of S. Pertina00x and subpallidum. All these species occured in a stream nearby Morungaba/SP, a city located 60 km easterly from Campinas/SP. All the species investigated were susceptible to P. Simulii. The pathogen occured frequently in epizootic levels in S. Pertinax and S. Subpallidumlarvae while it was uncommon in S. Pruinosum larvae. The infection frequencies of P. Simulii in the larvae of different sizes suggests that small larvae are the most affect by the disease. The different infection levels in the size classes and the fact that pupae and adults originated from infected individuals were free of infection indicate that the microsporidiosis is maintained in the field population by a mecanism of horizontal transmission...Note: The complete abstract is available with the full electronic digital thesis or dissertations
Mestrado
Ecologia
Mestre em Ciências Biológicas

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Dissertations / Theses on the topic 'Microsporea'

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