Dissertationen: „Maturation hormonale“

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Pham, Viet-Laï. „Aminopeptidase B : modélisation moléculaire et étude du site actif par mutagenèse dirigée“. Paris 6, 2007. http://www.theses.fr/2007PA066546.

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L’aminopeptidase B (Ap-B ; EC 3. 4. 11. 6) hydrolyse les acides aminés basiques en N-terminal de peptides et est impliquée dans la maturation d’hormones et probablement de neuropeptides selon un mécanisme original récemment mis en évidence. À ce jour, un seul de ses substrats physiologiques a été identifié, le glucagon qui, de par l’action successive de la NRD convertase puis de l’Ap-B, est transformé en miniglucagon. Ces deux hormones participent à la régulation de l’homéostasie du glucose chez les Mammifères. Une autre particularité de l’Ap-B est de présenter, in vitro, une activité résiduelle de type e��poxyde hydrolase, capable d’hydrolyser le leucotriène A4 (LTA4) en leucotriène B4, un médiateur lipidique de l’inflammation. A l’inverse, son plus proche parent phylogénétique, la Leucotriène A4 Hydrolase (LTA4H ; EC 3. 3. 2. 6) possède, en plus de son activité époxyde hydrolase, une activité aminopeptidase toutefois moins spécifique. Une analyse structurale et fonctionnelle de l’Ap-B est nécessaire pour mieux comprendre les mécanismes catalytiques de l’enzyme et pour parvenir à la conception d’inhibiteurs spécifiques, dont l’utilisation devrait nous éclairer sur l’ensemble de ses fonctions in vivo. Nous avons mis au point un système d’expression et de purification de l’Ap-B chez E. Coli avant d’entreprendre une analyse fonctionnelle par mutagenèse dirigée d’un certain nombre de résidus potentiellement impliqués dans l’activité de l’enzyme. Ces acides aminés ont été identifiés par alignement des séquences des protéines de la famille M1 à laquelle appartiennent l’Ap-B et la LTA4H. Cette étude a, par ailleurs, permis d’identifier 3 sous-familles distinctes d’aminopeptidases. Cette famille M1 est caractérisée par la présence d’un motif de fixation du cation Zn2+ de type HEXXHX18E. Les mutations des résidus de ce motif conduisent à une perte totale de l’activité de l’Ap-B, confirmant ainsi le rôle essentiel de ces résidus dans le mécanisme catalytique. La famille M1 est également caractérisée par la présence d’un second motif consensus (GXMEN). Nous avons également muté l’ensemble des résidus de ce second motif. Si les mutations des acides aminés M, E et N conduisent à une perte de l’activité, les mutations du résidu G en sérine ou proline donnent naissance à deux protéines actives. Le mutant G298S a des propriétés proches de l’enzyme sauvage, tandis que le mutant G298P présente une modification de sa spécificité de substrat (clivage de R, K, P et A), de son profil d’inhibition et de son activité en présence d’ions Cl-. L’analyse de ces mutants par dichroïsme circulaire et spectrométrie de fluorescence montre que les structures globales de ces enzymes ne semblent pas perturbées. Dix autres acides aminés ont également été mutés et leur étude fonctionnelle est en cours. Les similitudes structurales et fonctionnelles de l’Ap-B et de la LTA4H dont la structure 3D est connue, nous a permis de construire un modèle moléculaire de la structure de l’Ap-B. Ce modèle a été utilisé pour, d’une part, essayer de comprendre le rôle du résidu Glycine du motif GXMEN et, d’autre part, pour mettre en évidence un certain nombre de différences entre l’Ap-B et la LTA4H, en particulier au niveau du site actif et des propriétés potentielles d’interactions protéine-protéines de l’Ap-B. En parallèle, nous avons mis au point un second système d’expression et de purification de l’Ap-B à partir d’un vecteur baculovirus et de cellules d’insectes. Ce système nous permet d’obtenir une quantité suffisante d’enzyme pour mettre au point les conditions de cristallogenèse de la protéine
Aminopeptidase B (Ap-B ; EC 3. 4. 11. 6) cleaves basic residues at the N-terminus of peptides and participates in hormone and neuropeptide processing through an original mechanism recently described. The only known physiological substrate of Ap-B is the glucagon, which is processed into miniglucagon by NRD convertase and Ap-B. In mammals, these hormones are involved in the regulation of glucose homeostasis. One second characteristic of Ap-B is that the enzyme exhibits, in vitro, a residual ability to hydrolyze leukotriene A4 (LTA4) into the pro-inflammatory lipid mediator leukotriene B4. Inversely, LTA4 hydrolase (LTA4H ; EC 3. 3. 2. 6), the closest homologous protein of Ap-B, possesses, besides an epoxyde hydrolase activity, an aminopeptidase activity of broader specificity. Both proteins belong to the M1 family of Zn2+-aminopeptidases. A structure-function analysis is needed for a detailed understanding of the enzymatic mechanisms of Ap-B and to aid in the design of inhibitors, which could be used to determine its whole in vivo functions. In order to carry out a functional analysis by site-directed mutagenesis, we developed an expression system and a purification procedure of Ap-B using E. Coli. Amino acid residues potentially involved in the aminopeptidase activity are identified using alignments of primary structures of proteins from the M1 family. This study allowed us to identify 3 distinct M1 sub-families. This M1 family is characterized by the presence of a HEXXHXn=18E Zn2+- binding motif. Mutations of these residues lead to a total loss of activity and confirm their essential roles in catalysis. The major part of the M1 family members (Ap-B, LTA4H,…) constitutes the main sub-family and possesses a second consensus motif (GXMEN). Mutations of the M, E or N residues also lead to a total loss of aminopeptidase activity. Surprisingly, replacement of the conserved glycine into a serine or a proline created two new active enzymes. The G298S mutant exhibits properties similar to the wild type enzyme, whereas the G298P mutant shows a modification of its substrate specificity (recognizing R, K, P and A), its inhibition profile and its behavior towards Cl-. Fluorescence spectroscopy and circular dichroïsm analyses did not show any fundamental modification in the mutant structures. Ten other residues were mutated in the Ap-B primary structure and their functional studies are in progress. The sequence and catalytic similarities shared between Ap-B and LTA4H and the determination of the X-ray structure of LTA4H led us to build a 3D structural model of Ap-B. This model was used, on one hand, to better understand the enzymatic role of the glycine residue of the GXMEN motif and, on the other hand, to highlight functional differences between Ap-B and LTA4H, particularly at the level of their active site and of their proteinprotein interaction properties. In parallel, we also developed a second system of expression and purification of Ap-B using baculovirus and insect cells. This system allows us to purify a sufficient amount of protein for crystallogenesis assays

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Baribault, Hélène. „Régulation hormonale de la prolifération, de la maturation et de l'expression des cytokératines des cultures d'hépatocytes en voie de différenciation“. Doctoral thesis, Université Laval, 1986. http://hdl.handle.net/20.500.11794/33558.

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La régulation hormonale de la prolifération et de la différenciation cellulaire peut varier selon les types cellulaires ainsi que leur degré de transformation. Le but principal de ce travail était d'élaborer un système de cellules épithéliales en culture primaire et d'étudier les mécanismes de la régulation hormonale de leur croissance en fonction de leur capacité à exprimer certaines fonctions foetales et différenciées. L'élaboration d'un système de culture d'hépatocytes de rat nouveau-né, en voie de différenciation a permis d'étudier la régulation hormonale de la prolifération et de la différenciation des hépatocytes. Les hépatocytes de rat de 14 jours représentent une population de cellules diploïdes, qui sont synchronisées dans la phase Gi du cycle cellulaire au moment de l'isolement et qui expriment encore des fonctions immatures telle la production d' a-foetoprotéine. Suite à une stimulation par l'EGF et l'insuline ou l'EGF et le glucagon, les hépatocytes de rat de 14 jours ont une plus grande capacité à proliférer que les hépatocytes de rat adulte. Les seuls critères qui distinguent les populations d'hépatocytes de rats nouveau-né et adulte sont leur niveau de ploidie et leur degré de maturation. L'addition de dexaméthasone en présence de ces facteurs de croissance amènent une inhibition sélective de la production d'AFP par rapport à l'albumine, un changement généralement associé à une maturation des hépatocytes. De plus, la dexaméthasone induit une inhibition de la prolifération des hépatocytes en présence de EGF et de glucagon et non en présence d'EGF et d'insuline. Ces résultats mettent en évidence qu'il existe deux sentiers distincts par lesquels l'EGF peut être complémenté pour induire la prolifération des hépatocytes et que la dexaméthasone n'exerce un effet que sur celui utilisé par le glucagon. De plus, la prolifération et la maturation des hépatocytes peuvent être régulées de façon indépendante ou coordonnée. La dexaméthasone est le seul facteur parmi les facteurs testés capable d'induire une maturation des hépatocytes "in vitro". L'addition de DM50 ou de phénobarbital inhibe la prolifération des hépatocytes et permet de maintenir la production d ' -foetoprotéine ainsi que d'albumine. Parmi les événements induits précocement dans la phase préréplicative suite à une stimulation hormonale, plusieurs changements s'effectuent dans la synthèse, l'organisation et la phosphorylation des cytokératines. En effet, 1'addition d1 EGF induit une augmentation dans la phosphorylation de la cytokératine A sur le groupement tyrosine. Des analyses en immunofluorescence à l'aide d'anticorps monoclonaux dirigés spécifiquement contre les cytokératines A et D, anti-CK55 et anti-CK49 respectivement montrent que ce changement dans l'état de phosphorylation de la cytokératine A est associée à une réorganisation des filaments de cytokératines constituées de ces deux cytokératines A et D. D'autre part, la dexaméthasone induit une synthèse préférentielle des deux cytokératines majeures des hépatocytes, les cytokératines A et D. L'EGF n'influence pas cette réponse induite par la dexaméthasone. Cette néosynthèse préférentielle est associée à une inhibition sélective de la production d'a-foetoprotéine par rapport à l'albumine. Ces résultats montrent que les cytokératines sont vraisemblablement impliquées dans les réponses cellulaires induites par l'EGF et la néosynthèse de ces protéines est associée au programme de différenciation des hépatocytes.
Montréal Trigonix inc. 2018

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Ebiou, Jean-Claude. „Le rôle biologique de la thyrotropin-releasing hormone (TRH) dans le pancréas endocrine“. Paris 7, 1992. http://www.theses.fr/1992PA077056.

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L'objectif de ce travail est la recherche du rôle biologique de la TRH pancréatique. La TRH a été initialement isolée de l'hypothalamus et caractérisée comme pGlu-His-ProNH₂. Elle a ensuite été détectée dans le pancréas endocrine désigne comme deuxième site de synthèse du peptide. La TRH est synthétisée à partir d'un précurseur de haut poids moléculaire. La maturation complète de celui-ci génèrerait 5 molécules de TRH, et 7 peptides de connexion. Nous avons montré que la TRH secrétée par le pancréas a les mêmes caractéristiques chromatographiques que le peptide synthétique. La sécrétion de la TRH pendant le développement est stimulé par le glucose et l'arginine, tandis que ces mêmes secretagogues inhibent la sécrétion chez l'adulte. Fait intéressant, la sécrétion de la TRH augmente avec l’âge, en dépit de la chute des contenus pancréatiques. Nous avons caractérise deux peptides de connexion de la prepro-TRH: prepro-TRH160-169 et prepro-TRH178-199, dans des ilots de Langerhans, et le prepro-TRH178-199 dans le milieu de sécrétion. Concernant le rôle biologique de la TRH pancréatique, nous avons montré que: la TRH exogène stimule la sécrétion basale du glucagon; l'immunoneutralisation de la TRH endogène secrétée par l'anticorps anti-TRH inhibe significativement la sécrétion du glucagon induite par l'arginine, la sécrétion de somatostatine est légèrement inhibée. Sur une fistule pancréatique, la TRH inhibe la sécrétion exocrine des protéines, bicarbonates, et du sodium. Les résultats préliminaires sur les cellules acinaires indiquent une absence d'effet TRH. L'effet TRH, observe in vivo, serait medié par le système nerveux central. Au cours du développement, la TRH n'a pas d'effet sur les secrétions d'insuline et glucagon. Nous pensons qu'elle agirait sur le processus de prolifération des cellules insulaires. La TRH stimule la sécrétion du glucagon des cellules alpha. Il serait intéressant de rechercher l'action biologique des deux peptides de connexion. La détermination du mécanisme d'action de la TRH pancréatique implique la caractérisation des sites de liaison spécifiques. Ce travail a été publié dans: Endocrinology 1992, 130(3):1371-1379; Endocrinology 1992, 131(2) (à paraitre en aout); prostate tumeurs 1991, (7):9-10 et 1992(9):6-7.

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Puccio, François. „Influence de l'hydrocortisone, de l'egf, de la bombesine et du grf sur la proliferation cellulaire et la maturation du tractus gastrointestinal et du pancreas chez le jeune rat non sevre“. Paris 6, 1988. http://www.theses.fr/1988PA066497.

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Liu, Mingchun. „Functional characterization of Sl-ERF.B3, a member of the large multi-gene family of Ethylene Response Factor in tomato (Solanum lycopersicum)“. Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0089/document.

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Les derniers acteurs de la voie de signalisation à l’éthylène sont des facteurs de transcription appelés ERF (Ethylene Response Factors). La connaissance de leur rôle spécifique dans la régulation des processus développementaux dépendant de l’éthylène reste limitée. Les travaux présentés dans la thèse concernent la caractérisation fonctionnelle du gène Sl-ERF.B3, un membre de cette grande famille de régulateurs transcriptonnels dans la tomate (Solanum lycopersicum). Utilisant une stratégie répresseur dominant ; il est montré en particulier que ce gène intervient dans la mise en place de la réponse à l’éthylène et dans le contrôle de la maturation du fruit. L’expression d’une construction ERF.B3-SRDX, une version chimérique de Sl-ERF.B3 fusionné à un domaine répresseur de type EAR, entraine des phénotypes pléotropiques aussi bien dans la signalisation de l’éthylène que dans le développement des parties végétatives et des organes reproducteurs. Ainsi, une altération de la triple réponse à l’éthylène est constatée chez les lignées transgéniques et au stade adulte, les plantes présentent des phénotypes d’épinastie des feuilles, de sénescence prématurée des fleurs et d’abscission accélérée des fruits. L’ensemble de ces observations est corrélée avec une modification de l’expression de gènes impliqués dans la biosynthèse et la réponse à l’éthylène. Ces données suggèrent que ERF.B3 intervient dans un mécanisme de rétro-control de la réponse à l’éthylène en agissant à la fois sur les gènes de biosynthèse et de signalisation de l’hormone. Au niveau du fruit, la sur-expression d’ERF.B3-SRDX entraine une modification du processus de maturation avec un retard notable de l’avènement de l’acquisition de la compétence à murir. Cependant, une fois la maturation initiée, elle s’accompagne d’une forte production d’éthylène et d’une accélération du ramollissement du fruit. A l’inverse, l’accumulation de pigment est inhibée par altération de la voie de biosynthèse des caroténoïdes. Ces données phénotypiques sont corrélées avec le niveau d’expression des gènes clés impliqués dans ces processus. Les résultats indiquent que dans les lignées transgéniques, il y a découplage de certaines caractéristiques de la maturation du fruit et permettent de mettre en lumière le rôle d’ERF.B3 dans la régulation des processus de développement dépendant de l’éthylène chez la tomate
Ethylene Response Factors (ERFs) are known to be the last transcription factors of the ethylene transduction pathway. Their specific role in ethylene-dependent developmental processes remains poorly understood. This work demonstrated a specific role of Sl- ERF.B3, a member of the ERF gene family in tomato (Solanum lycopersicum), in mediating ethylene response and fruit ripening through a dominant repressor strategy. ERF.B3-SRDX dominant repressor etiolated seedlings displayed partial constitutive ethylene-response in the absence of ethylene and adult plants exhibited typical ethylenerelated alterations such as leaf epinasty, premature flower senescence and accelerated fruit abscission. The multiple symptoms related to enhanced ethylene sensitivity correlate with the altered expression of ethylene biosynthesis and signaling genes, suggesting the involvement of Sl-ERF.B3 in a feedback mechanism regulating components of ethylene production and response. In addition, over-expression of ERF.B3-SRDX in tomato results in alterations in both fruit morphology and ripening process. The attainment of competence to ripen is dramatically delayed in ERF.B3-SRDX fruits but once ripening proceeds it is associated with high climacteric ethylene production and enhanced fruit softening while pigment accumulation is strongly reduced. Moreover, a number of genes involved in the fruit ripening process showed expression pattern deviating from that of wild type. These data suggest a putative role of Sl-ERF.B3 in the transcriptional network underlying the ripening process and uncover a mean for uncoupling some of the main features of fruit ripening such as fruit softening and pigment accumulation. Overall, the study highlighted the importance of an ERF gene in ethylene-mediated developmental processes such as plant growth and fruit ripening

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Martin, Niall M. B. „Protein turnover in Salmonids : sexual maturation and hormonal control“. Thesis, University of Aberdeen, 1990. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU548688.

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Aspects of tissue protein metabolism were studied in different groups of Atlantic salmon (Salmo salar). Firstly, 2 groups of sea water salmon were fasted for 3 and 5 days, prior to the measurement of tissue fractional rates of protein synthesis (ks, %day), using the method of 3H-phenylalanine flooding. The sensitivity of liver and gill to a short-term fast was indicated by their reduced rates of ks, while in other tissues such as ventricle, stomach and red muscle protein synthesis was unaffected. Both liver and gill are tissues which show the greatest capacities to synthesise protein, expressed by their high RNA contents. The response of tissue protein metabolism to sexual maturation was investigated in 2 groups of salmon undergoing river migration, tissues were analysed in both July salmon (sexually maturing) and in more mature October salmon. White muscle contributed most of the amino acids required during maturation, denoted by the high loss of protein and RNA from the flesh of the salmon by October. Red muscle, gill and ventricle were tissues which were protected during maturation, showing only slight changes in rates of protein metabolism. Liver, stomach and ovary on the other hand increased their RNA and protein contents, and showed increased rates of protein synthesis. The liver however, displayed a greater increase in its RNA concentration than protein i.e. the liver by October had increased its capacity to produce large amounts of export proteins. Despite the overall loss by stomach and other visceral tissues of protein and RNA, the stomach by October showed a dramatic 5-6 fold increase in its rate of protein synthesis. It was concluded that smooth muscle may have a particular role or function in the sexually mature fish. Factors controlling these in vivo changes in protein synthesis were investigated using rainbow trout (Oncorhynchus mykiss) isolated hepatocytes and a smooth muscle preparation in vitro . Anabolic actions on hepatocyte protein synthesis were exhibited by insulin, thyroxine and in the absence of fetal calf serum by triiodothyronine. The synthetic glucocorticoid, dexamethasone, unlike its actions in muscle, also exhibited an anabolic action on hepatocytes, by raising RNA and protein levels in cells from immature fish, while increasing protein synthesis rates in liver cells of sexually mature fish. Estradiol, like dexamethasone, stimulated rates of protein synthesis over 24 hours. However, hydroxyprogesterone caused no change in protein synthesis and decreased the effect of estradiol. Estradiol also increased protein synthesis rates in smooth muscle by some 30%. However, hydroxyprogesterone, as in liver cells, caused no stimulation of protein synthesis and again decreased the estradiol stimulated ks. It was proposed that estradiol is one of the factors involved in increasing the ks in the stomach of the sexually maturing salmon, while progesterone regulates the action of estradiol towards the end of sexual maturation, when such an effect of estradiol on liver and smooth muscle ks is unnecessary.

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Bussieres, Laurence. „Etude de la na-k-atpase renale par cytochimie quantitative“. Paris 6, 1987. http://www.theses.fr/1987PA066289.

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Taranger, Geir Lasse. „Sexual maturation in Atlantic salmon, Salmo salar L.; aspects of environmental and hormonal control /“. Online version, 1993. http://bibpurl.oclc.org/web/32827.

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Benedet, Perea Susana. „Growth hormone and somatolactin function during sexual maturation of female Atlantic salmon /“. Göteborg : Göteborg University, Department of Zoology/Zoophysiology, 2008. http://gupea.ub.gu.se/dspace/bitstream/2077/18305/4/gupea_2077_18305_4.pdf.

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Pursell, Natalie W. „Hsp90-Mediated Maturation of Kinases and Nuclear Steroid Hormone Receptors: A Dissertation“. eScholarship@UMMS, 2011. https://escholarship.umassmed.edu/gsbs_diss/535.

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Among heat shock proteins, Hsp90 is unusual because it is not required for the proper folding of most cellular proteins but rather is disproportionally linked to the activation of signal transduction proteins including over forty kinases and many steroid hormone receptors. Mutated forms of many Hsp90 clients are causative agents in cancer, making Hsp90 a promising pharmacological target. Many small molecular inhibitors have been identified that competitively bind to the ATP binding site of Hsp90, some of which are in clinical trials as anticancer agents. Although the activation of kinase and hormone receptor clients by Hsp90 and its co-chaperones has been extensively studied, the molecular mechanism of client protein activation is poorly understood. Hsp90 is a dimeric chaperone containing three domains: the N-terminal (N) and middle (M) domains contribute directly to ATP binding and hydrolysis and the C-terminal (C) domain mediates dimerization. At physiological concentration, Hsp90 predominantly forms dimers, but the possibility that full-length monomers might also function in cells has not been tested. In Chapter 3, we used a single-chain strategy to design a full-length Hsp90 monomer (NMCC). The resulting construct was predominantly monomeric at physiological concentration and did not function to support yeast viability as the sole Hsp90. NMCC Hsp90 was also defective at ATP hydrolysis and the activation of kinase and steroid hormone receptor clients in yeast cells. The ability to support yeast growth was rescued by the addition of a coiled-coil dimerization domain, indicating that the parental single-chain construct is functionally defective because it is monomeric. After finding that a full-length Hsp90 monomer containing only one ATPase site was unable to support yeast viability or activate Hsp90 clients, we set out to further explore the role of ATPase activity in client protein activation. Approximately 10 % of the yeast proteome binds to Hsp90 making it important to study Hsp90 function in the cellular environment where all binding partners are present. In Chapter 4, we observed that co-expression of different Hsp90 subunits in Saccharomyces cerevisiae caused unpredictable synthetic growth defects due to cross-dimerization. We engineered super-stabilized Hsp90 dimers that resisted cross-dimerization with endogenous Hsp90 and alleviated the synthetic growth defect. We utilized these super-stabilized dimers to analyze the ability of ATPase mutant homodimers to activate known Hsp90 client proteins in yeast cells. We found that ATP binding and hydrolysis by Hsp90 are both required for the efficient maturation of the glucocorticoid hormone receptor (GR) and v-src confirming the critical role of ATP hydrolysis in the maturation of steroid hormone receptors and kinases in vivo. In addition to its role in the activation of signal transduction client proteins, Hsp90 has been shown to suppress the in vitro aggregation of numerous hard-to-fold proteins. In Chapter 5, we examine the role of charge in Hsp90 anti-aggregation activity. The charge on Hsp90 is largely concentrated in two highly acidic regions. We found that deletion of both charge-rich regions dramatically impaired Hsp90 anti-aggregation activity. Addition of an acid-rich region with a distinct amino acid sequence to our double-deleted Hsp90 construct rescued the anti-aggregation activity of Hsp90 indicating that the net charge contributes to its anti-aggregation activity. The in vitro anti-aggregation activity of Hsp90 studied in Chapter 5 occurs in the absence of ATP. However, all of the biologically important functions of Hsp90 in cells identified to date, including the maturation of kinases and nuclear steroid hormone receptors, clearly require ATP hydrolysis. Why does Hsp90 robustly hinder the aggregation of hard-to-fold proteins without ATP in vitro, but in vivo uses ATP hydrolysis for all of its essential functions? By utilizing separation of function Hsp90 variants (that specifically lack in vitro anti-aggregation activity) we have begun to address this question. We find that anti-aggregation deficient Hsp90 is unable to support yeast growth under stressful conditions, potentially due to reduced cellular expression. Interestingly, the ATP-independent anti-aggregation activity of Hsp90 has no measureable impact on cellular function. Thus, hindering the aggregation of most hard-to- fold proteins by Hsp90 (independent of ATP hydrolysis) does not appear to be important for cell function. These results suggest a cellular model where the Hsp40/60/70 machinery is responsible for hindering the aggregation of most hard-to-fold proteins while Hsp90 assists in the maturation of a select set of clients in an ATP-dependent fashion, potentially aided by its inherent anti-aggregation properties.

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Richings, Nadine Maree. „Growth, development and maturation of the marsupial follicle and oocyte /“. Connect to thesis, 2004. http://eprints.unimelb.edu.au/archive/00001516.

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Schauer, Stephanie Nicole. „Role of luteinising hormone in ovarian follicle development and maturation in the mare“. Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/11731.

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Luteinising hormone (LH) is a crucial regulator of ovarian follicle maturation, ovulation and luteinisation. Development of healthy follicles and fertile ovulation can only occur within a specific range of circulating LH concentrations, with differing upper and lower limits depending on the stage of the oestrous cycle. The objective of the three studies in this thesis was to investigate the effects of both physiological and non-physiological circulating LH levels on equine follicular maturity by examining ovulatory and steroidogenic capacity, gene expression profiles and miRNA expression in ovulatory-size follicles at various stages of the oestrous cycle and/or in response to supplementation with LH. The aim of the first study was to investigate the hypothesis that deficient circulating LH is a primary cause for the inability of equine follicles to ovulate during the physiological anovulatory season. A LH-rich equine pituitary fraction (eLH) given twice daily to early transitional mares did not restore steroidogenic capacity of the ovulatory-size follicle or advance the onset of the natural breeding season; however, it significantly stimulated follicular growth to a level similar to that occurring during the normal oestrous cycle. The results demonstrated that a deficiency in LH is critically involved in reduced follicle growth during the anovulatory season. The second study examined the effects of elevated circulating LH levels early during follicle development on follicle maturation and ovulatory ability in cycling mares, with the hypothesis that excessive LH would disrupt ovulation and produce haemorrhagic anovulatory follicles (HAFs). Treatment with eLH or a luteolytic dose of prostaglandin F2α (to stimulate an increase in endogenous levels of LH) did not have any effects on follicle growth or ovulation, but did impair follicular production of androstenedione and insulin-like growth factor 1 (IGF1), suggesting a deleterious effect of high LH on follicle and oocyte maturation. The third study examined the expression of different follicular factors associated with follicle maturation as well as microRNAs (miRNAs) in ovulatory-size follicles naturally developing under different LH milieus (oestrus, dioestrus and spring transitional period). Progesterone and IGF1 were significantly reduced in follicles developing in a low LH environment (dioestrus and transition). All four miRNAs measured, miR-378, miR-542, miR-202 and miR-21 were found at higher levels in subordinate follicles than in preovulatory follicles during oestrus. In addition miR- 202 and miR-21 were significantly increased in transitional follicles relative to oestrous follicles. The results of this study indicate that follicles developing during both the spring transitional and dioestrous periods are developmentally immature and suggested potential important roles of miRNAs in follicle maturation in the horse. In summary, although LH is a key factor promoting follicular growth, it is by itself not sufficient to restore steroidogenic activity in transitional follicles. Elevated LH levels during follicle development do not disrupt ovulation, but induce changes in follicular fluid factors related to follicle maturation and oocyte quality. Follicles developing under different LH milieus show altered miRNA expression, suggesting an important role of miRNAs in follicle maturation.

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Nadaf, Somayyeh. „Analyse protéomique et transcriptomique de la maturation folliculaire“. Thesis, Tours, 2010. http://www.theses.fr/2010TOUR4037.

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La compréhension des mécanismes cellulaires et moléculaires qui sont mis en jeu au moment de la croissance et la maturation pré-ovulatoire induite par la LH, permettra de définir des marqueurs de qualité et de maturité du follicule destiné à ovuler, et ainsi de mieux anticiper le moment de l’ovulation. L’objectif majeur de cette thèse était d’identifier certain des facteurs régulateur impliqués dans la maturation folliculaire par deux approches globales d’analyse protéomique et transcriptomique. La première étude a permis d’établir pour la première fois les cartes protéiques du liquide folliculaire équin et canin. Les analyses comparatives des liquides folliculaires provenant de différents stades physiologiques n’ont montré, dans nos conditions expérimentales, que peu de différences. Nos résultats obtenus dans la deuxième étude indiquent que les différentes méthodes enrichissement du liquide folliculaire peuvent améliorer, pour certaines de manière conséquente, la résolution des gels 2D-PAGE. Notre étude transcriptomique globale a révélé un groupe de gènes différentiellement exprimés dans les cellules folliculaires aux différents stades étudiés. Ces gènes sont potentiellement impliqués pendant le développement folliculaire dans l’espèce équine. Les deux approches (protéomique et transcriptomique) que nous avons utilisées au cours de ce travail sont complémentaires car la connaissance des gènes exprimés par les cellules folliculaires peuvent permettre d’identifier certains gènes codant pour des protéines sécrétoires retrouvées dans le liquide folliculaire
An understanding of the cellular and molecular mechanisms involved in the growth and maturation of the preovulatory follicle induced by LH, will help us to understand and identify the markers of quality and maturity of the follicle destined to ovulate, and better anticipate the time of ovulation. The main objective of this thesis was to identify some regulatory factors involved in follicle maturation using two global approaches: proteomic and transcriptomic analysis. The first study established for the first time the protein map of equine and canine follicular fluids. The comparative analyses of follicular fluid from different physiological stages were shown little or no difference in our experimental conditions. Results obtained with the second study suggested that between depletion and enrichement methods, the enriched follicular fluid can improve for some consistent manner, the resolution of 2D-PAGE gels. Our global transcriptomic study revealed a group of genes differentially expressed in follicular cells at different physiological stages. These genes are potentially involved during follicle development in the equine species. The two approaches (proteomic and transcriptomic) that we used in this work are complementary, as the knowledge of genes expressed by follicle cells can help to identify some genes coding for secretory proteins secreted in follicular fluid

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Davies, Katie Louisa. „Developmental regulation of mitochondrial function in ovine fetal skeletal muscle“. Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/275596.

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Skeletal muscle is a highly metabolically active tissue, both in the adult and the fetus. Mitochondria are essential in providing energy in the form of ATP from the oxidative metabolism of carbohydrates, fats and amino acids. Mitochondrial function is influenced by the abundance and activity of the complexes comprising the electron transfer system (ETS) and the balance between mitochondrial fusion and fission. Any factors which affect the development of skeletal muscle, and mitochondria in particular, may have an impact not only on neonatal health but also on the metabolic health of the adult offspring. However, the normal developmental profile of skeletal muscle mitochondrial function as the fetus prepares for the increased metabolic challenges associated with extrauterine life, is not well characterised. The hormones, cortisol and triiodothyronine (T3) are known to be crucial in the maturation of several physiological processes during late gestation. Further, their role in regulating adult metabolism is well-documented. However, whether they play a role in regulating fetal mitochondrial function is unknown. Using fetal sheep, the aims of this project were twofold: 1) to determine any changes in skeletal muscle mitochondrial function which occur over the last third of gestation and in the first two days of neonatal life and 2) to determine any regulatory roles of cortisol and T3 in these developmental changes. Mixed fibre-type skeletal muscle was collected from fetuses at 3 time points over late gestation and from newborn lambs. In addition, skeletal muscle samples were taken from fetuses which had been thyroidectomised (TX) and fetuses infused with either T3 or cortisol. Respirometry, enzyme assays, qRT-PCR and western blotting were carried out on the skeletal muscle samples in order to assess mitochondrial parameters. Mitochondrial activity, as measured by carbohydrate- and fat- stimulated ADP-coupled oxygen uptake, increased with age in a thyroid hormone dependent manner, rising predominantly postnatally. Mitochondrial density, abundance of ETS complexes I-IV and ATP-synthase and expression of the adenine nucleotide transferase 1 and mitofusin 2 were all positively influenced by age, with the natural prepartum rise being prevented in the thyroidectomised fetuses. However, T3 infusion alone was insufficient to raise any of these factors prematurely. Cortisol infusion resulted in an increase in some aspects of mitochondrial oxidative capacity in a muscle-specific manner. Overall, the data presented shows that there are developmental changes in skeletal muscle mitochondria during the perinatal period. They also suggest that these changes are regulated by both cortisol and thyroid hormones in preparation for birth, although neither hormone alone was sufficient to induce all the functional changes.

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Scougall, Kathleen. „Maturation of pro-hormone convertases PC2 and PC3 and their interaction with the neuroendocrine protein 7B2“. Thesis, University of Aberdeen, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301302.

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The activation of many pro-hormones occurs through cleavage at pairs of basic residues and is mediated by two serine proteases, PC2 and PC3. Like their substrates, they are also synthesised as inactive precurors (pro-PC2 and pro-PC3). Maturation is autocatalytic and requires removal of the N-terminal pro-peptide. Pro-PC3 matures within the endoplasmic reticulum (ER), whereas maturation of pro-PC2 proceeds within the later compartments of the Golgi network (TGN)/secretory vesicle (SV) and is thought to be regulated by 7B2. In this study the molecular basis for the differences in the maturation location and the interaction with 7B2 was examined by performing domain swap and site directed mutagenesis experiments. The mutant constructs were analysed within an in vitro cell free system. The results suggest that the oxyanion hole residue (Asp³¹⁰) of pro-PC2 restricts maturation to a late secretory compartment and is important for the interaction with 7B2. Mutation of this residue to resemble that of PC3 (Asp310Ans), altered pro-PC2 maturation from a TGN/SV like environment to an ER like environment. Maturation of pro-PC2, but not pro-PC3, was shown to be inhibited by 7B2. Residue Asp³¹⁰ of PC2 was necessary to mediate this interaction. When a similar mutant of PC3 was created to resemble PC2 (Asn309Asp), this residue was not sufficient to alter the maturation profile of pro-PC3 nor was it able to confer 7B2 sensitivity. The pro-region of PC2 was sufficient to alter maturation of PC3 from the ER-like compartment to a TGN/SV-like compartment, but was not able to confer 7B2 sensitivity onto PC3. This study also demonstrated that a basic cluster (HHKQQ⁸⁸) of pro-PC2 was important for delaying maturation to a late compartment and that the residue Phe¹⁰⁴, was important for efficient maturation. Mutational analysis of pro-7B2 revealed that a region within residues 1-151 was important for the interaction with pro-PC2.

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Labbé, André. „Contribution a l'etude des phenomenes de croissance et de maturation pulmonaire antenataux chez l'homme (doctorat : biologie du developpement)“. Clermont-Ferrand 1, 1991. http://www.theses.fr/1991CLF1MM07.

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Gagné, Séverine. „Implication de l'équilibre hormonal dans les mécanismes de maturation phénolique du raisin : étude du rôle de l'acide abscissique sur la composition et la biosynthèse des tanins de la pellicule“. Bordeaux 2, 2007. http://www.theses.fr/2007BOR21457.

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La maturation de la pellicule du raisin est un phénomène complexe se caractérisant par des changements structuraux importants et l’accumulation de composés d’intérêt œnologique, dont les tanins. Malgré leurs propriétés biologiques et organoleptiques essentielles pour la qualité du fruit et des vins, peu de travaux concernent leur métabolisme et les modes de régulation de leur biosynthèse. Néanmoins, le statut hormonal de la baie a été plusieurs fois cité comme mode de régulation possible. Après avoir montré que l'équilibre hormonal, la maturation technologique et phénolique ainsi que l'accumulation des composés phénoliques pouvaient être modulés par l'apport exogène d'acide abscissique (ABA) quelques jours après la nouaison, nos résultats ont mis en évidence les modes d'action de ce régulateur dans la biosynthèse des tanins. Il agit d'une part sur l'activité des enzymes impliquées dans cette voie et l’expression des gènes qui les codent et, d'autre part, sur la composition, la structure et la localisation des tanins. Quel que soit le cépage (Cabernet-Sauvignon, Sémillon) ou le modèle d'étude (plein champ, culture cellulaire in vitro), tous nos travaux s'accordent pour confirmer le rôle prépondérant de l'ABA comme déclencheur de la véraison et modulateur du métabolisme des tanins. Les courbes d'évolution des teneurs en tanins ainsi que les profils d'activité enzymatique et d'expression des gènes ont permis d'émettre l'hypothèse d'une biosynthèse précoce de ces composés avant la formation de la baie. Cela a été confirmé par l'étude des tanins dans les fleurs et les baies juste nouées, démontrant le déterminisme précoce de ce métabolisme.

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Allet, Cécile. „Gliogenèse dans l'hypothalamus au cours du développement postnatal : implication dans le contrôle de la maturation sexuelle femelle“. Lille 2, 2006. http://www.theses.fr/2006LIL2S051.

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Notre travail propose de déterminer l'implication de la néogenèse postnatale dans la maturation des neurones hypothalamiques à GnRH, nécessaires à l'initiation de la puberté. Un nombre important de cellules prolifératives est observé dans l'hypothalamus postnatal à différents intervalles de temps après injection de BrdU. 25% des corps cellulaires à GnRH sont morphologiquement associés avec des cellules différentiées générées à P8. Par ailleurs, le nombre de ces cellules BrdU+ double entre P8 et P15. Cette vague de néogenèse précède et accompagne la première activation centrale de l'axe reproducteur. De plus, les cellules nouvellement générées se différencieraient en astrocytes plutôt qu'en neurones. Des expériences de neurosphères in vitro suggèrent la présence de cellules progénitrices multipotentes dans l'hypothalamus. Ces résultats montrent l'existence d'une néogenèse dans l'hypothalamus postnatal et suggèrent que la genèse de nouvelles cellules favorise l'initiation la puberté
The initiation of mammalian puberty requires an increased pulsatile secretion of GnRH from specialized neurons of the hypothalamus controlling sexual development. We have identified newborn cells by injecting BrdU at various intervals thereafter. We report that during sexual maturation a host of new cells is generated in the hypothalamus. This wave of cell neogenesis precedes and accompanies the first gonadal independent GnRH-driven activation of the reproductive axis. By P15 a significant fraction of GnRH neuronal cell bodies is morphologically associated with differentiated cells that were born on P8. Moreover, upto 35% of the cells closely associated with GnRH axon terminals entering cell cycle remain associated with this neurosecretory system once differenciated. These results raise the exciting possibility that birth of new cells is a component of the maturational process required for the activation of GnRH neuronal function at the onset of puberty

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Deytieux, Christelle. „Maturation du raisin : étude de la relation entre l'équilibre hormonal et les facteurs impliqués dans l'évolution des parois cellulaires de la pellicule“. Bordeaux 2, 2005. http://www.theses.fr/2005BOR21271.

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La maturation du raisin est caractérisée par de nombreux changements physiologiques. Le tissu pelliculaire nous intéresse plus particulièrement puisque son intégrité est prédominante pour l'obtention d'un raisin de qualité. Les changements observés sont sous le contrôle du statu hormonal. Notre étude apporte de nouvelles données sur l'importance de l'AIA et des polyamines pendant la maturation et le ramollissement du fruit. Nous avons souligné le rôle majeur de l'AIA dans le déclenchement de la véraison. Des protéines impliquées dans les changements structuraux des parois cellulaires ont été étudiées d'un point de vue de l'activité enzymatique et de l'expression génique. Nous nous sommes plus particulièrement intéressés à la PME, la PG, la XET ainsi que d'autres activités glycolytiques. L'utilisation de plusieurs traitements spécifiques nous a conduit à mieux appréhender les interactions entre l'équilibre hormonal, le contrôle de la maturation et les protéines impliquées dans l'évolution des parois. De plus, une approche protéomique, spécialement adaptée à la pellicule du raisin, nous a permis d'identifier des protéines différentiellement exprimées à trois stades clés de la maturation : début véraison, fin véraison et maturité
Grape berry ripening is characterized by numerous physiological changes. Skin tissue is particularly interesting because integrity is a predominant determinant for producing a good grape quality. Changes that occured during ripening are under hormonal statue. Our studies supply new data about the importance of free abscisic acid, indole acid (IAA) and polyamines during ripening and softening. We underline the preponderant role of IAA in triggeering veraison. Some protein potentially responsible for the cell wall modifications were studied in terms of enzyme activity and transcriptional activity. We focussed on the importance of pectin methylesterase, polygalaturonase, xyloglucan endo transglycosidase and other glycosidase activities during skin ripening. Use of several specific treatments has allowed us to underscore the impôrtance of hormonal balance in the control of grape ripening and cell wall degrading enzymes. Otherwise, a proteomic approach especially adapted to the skin tissue led us to identify proteins differentially expressed at three key stages of development : beginning coloured, full coloured and maturity

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Tata, Brooke. „Evidence For the Requirement of the Vesicular Protein, Rabconnectin-3α, in the Activation and Maturation of the Gonadotropin-Releasing Hormone (GnRH) Neuronal Network“. Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCC132.

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Les neurones GnRH sont les principaux régulateurs de l'axe HPG de la puberté et de la fonction de reproduction normale. La puberté se caractérise par une maturation des circuits neuronaux. Cette période de maturation sexuelle dépend ainsi de profondes modifications de la régulation des connexions synaptiques et de la plasticité des neurones à GnRH. Les mécanismes responsables de ces modifications restent mal compris, mais ceux-ci pourraient dépendre de modifications structurales et de la maturation des neurones à GnRH. On a identifié une mutation dans le gène DMXL2, qui code pour la rabconnectin-3α (rbcn3-α), une protéine d'échafaudage liée à Rab3, qui joue un rôle dans la plasticité synaptique et le relargage de neurotransmetteurs. Rbcn3-α pourrait donc participer à la plasticité et la maturation des neurones à GnRH. Notre objectif a été de caractériser la rôle de rbcn3-a dans les neurones à GnRH. Rbcn3-α est exprimé dans des neurones GnRH. De souris knockout conditionnel de Dmxl2 dans les neurones entraine un retard pubertaire et une infertilité associés à une perte significative du nombre de neurones GnRH. Pour clarifier le rôle de rbcn3-α dans les perturbations neurodéveloppementales de GnRH, nous avons produit des souris Nes-Cre::Dmx12 et GnRH-Cre::Dmx12. On a ainsi montré que les neurones GnRH immatures ne peuvent pas être activés. De souris présentent un déficit de signalisation glutamatergique dans l'hypothalamus et un défaut du contrôles-circadiens de l'ovulation. Rbcn3- α participe à la maturation et l'activation des neurones à GnRH une étape indispensable à l'initiation de la puberté
Gonadotropin-releasing hormone (GnRH) neurons are the master regulatory output of the hypothalamus-pituitary-gonadal axis for pubertal onset. Puberty is characterized by the maturation of neuronal circuits where synaptic inputs change in the regulation of GnRH neurons to achieve pubertal onset. The mechanisms underlying these modifications remain elusive, but could be linked to the maturation of GnRH neurons. Deviations in the regulation of GnRH neurodevelopment cause pubertal delay and fertility defects. We discovered a complex neurodevelopmental disorder in human patients with a mutation in DMXL2, which encodes a vesicular protein rabconnectin-3α (rbcn3-α). Rbcn3-α is a scaffolding protein important for neuron plasticity and neurotransmitter release and can be a link between neuron plasticity and neurodevelopmental disorders with pubertal defects. Conditional neuronal Dmx12 knock-out mice (Nes::Cre;Dmx12loxp/wt) exhibitpubertal deficits, infertility, and a loss of GnRH neurons. We found loss of neuronal Dmx12 impedes GnRH neuron maturation, where immature GnRH neurons are unable to respond to potent stimuli compounded with disruptions in the circadian timed LH surge. These data indicate immature GnRH morphologies disrupts the functioning of GnRH neuronal networks. Moreover, Nes::Cre;Dmx12loxp/wt mice have decreased hypothalamic VGluT2 and increased NMDAR1 mRNA. Cre-dependent viral filling of GnRH neurons in GnRH::Cre ' Dmx12wt/wt mice showed rbcn3-a-containing terminals contact GnRH dendritic spines associated with VgluT2 terminals, and in the GnRH soma. We demonstrate rbcn3-a as a key regulator of pubertal onset and the maturation and activation of GnRH neurons

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Romão, Daniela 1993. „Systemic effects of chromosomal instability induced tumorigenesis : A role of JAK/STAT and cytokine secretion in coupling inflammation to maturation defects in Drosophila“. Doctoral thesis, TDX (Tesis Doctorals en Xarxa), 2021. http://hdl.handle.net/10803/672640.

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Alterations in developmental transitions are common among animals to compensate for growth disturbances. These variations are usually a consequence of altered steroidal hormone production resulting in puberty delays. Inflammation and high cytokine release seem to be behind these altercations, although in humans no concrete model has been put forward. Here we use a Drosophila epithelial model of Chromosomal Instability-driven malignant transformation to unravel a role of the Upd3 cytokine and JAK/STAT signaling in coupling the development of these tumors with a delay in metamorphosis. We present evidence that Upd3, produced by malignant and adjacent wild type cell populations, signals to the prothoracic gland, an endocrine tissue primarily dedicated steroid hormone production, to activate JAK/STAT and the bantam miRNA and to delay metamorphosis. These results identify a new regulatory network influencing ecdysone biosynthesis and provide experimental evidence that malignant tissues can have a direct effect on steroidal hormone regulation.
Las alteraciones durante las transiciones del desarrollo son comunes en los animales como compensación ante perturbaciones en el crecimiento. Dichos cambios, son generalmente una consecuencia de afectar la producción de hormonas esteroides, que puede ocasionar retrasos de la pubertad. Tanto la inflamación, como la alta liberación de citoquinas, parecen ser responsables de dichas variaciones, sin embargo, para estudios humanos no se ha presentado ningún modelo concreto que verifique este hecho. En este trabajo, utilizamos un modelo epitelial de transformación maligna impulsada por inestabilidad cromosómica en Drosophila para revelar el papel de la citoquina Upd3 y de la señalización de JAK/STAT en el retraso en la metamorfosis durante el desarrollo tumoral. Presentamos evidencia de que Upd3, producida por poblaciones malignas y por tejidos adyacentes de células normales, es capaz de señalar a la glándula protorácica, responsable por la producción de hormonas esteroideas, para activar JAK/STAT y el miRNA de Bantam, retrasando así la metamorfosis. A la luz de estos resultados, identificamos una nueva red reguladora que afecta a la biosíntesis de ecdysona y proporcionamos la evidencia experimental de que los tejidos malignos pueden tener un efecto directo en la regulación de la hormona esteroidea.

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Bolling, Laura Clayton. „The Effect of Growth Hormone on Pig Embryo Development in Vitro and an Evaluation of Sperm-Mediated Gene Transfer in the Pig“. Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/35823.

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The objective of part one of this study was to determine if the presence of porcine growth hormone (pGH) during oocycte in vitro maturation (IVM) affected subsequent embryo development. Pig cumulus-oocyte complexes (COC) (n=987) were aspirated from slaughterhouse derived ovaries and cultured in BSA-free NCSU 23 medium containing porcine follicular fluid (10% v/v), cysteine (0.1 mg/ml) and hormonal supplements (eCG and hCG, 10 IU/ml each), 10 ng/ml EGF, and with or without pGH (100 ng/ml) for 22 h. The COC were then cultured in the same medium with or without 100 ng/ml pGH, but without hormonal supplements for an additional 22 h. After the completion of maturation culture, cumulus cells were removed and oocytes were co-incubated with frozen-thawed spermatozoa for 8 h. Putative embryos were transferred to NCSU 23 containing 0.4% BSA and cultured for 144 h. Embryo development was assessed on d 6 of culture. The treatment groups were as follows: treatment 1 = control group cultured in IVM medium alone; treatment 2 = 100 ng/ml pGH present of the first 22 h of maturation culture and absent for the second 22 h of maturation culture; treatment 3 = 100 ng/ml pGH absent for the first 22 h of maturation culture, but present for the second 22 h of maturation culture; and treatment 4 = 100 ng/ml pGH present throughout the entire IVM period. Embryos were visually scored for developmental stage at 144 h following fertilization. Each oocyte in the study received a developmental score, based on a scale of 1 = uncleaved, 2 = 2-cell embryo, 3 = 4- to 8-cell embryo, 4 = 9- to 16-cell embryo, 5 = morula, and 6 = blastocyst. The addition of pGH did not affect porcine embryo development as compared to the control (1.57 Â± .08, 1.67 Â± .08, 1.47 Â± .08, and 1.60 Â± .08, respectively; P > .10). Replicates within the study differed significantly from each other (P < .01) primarily because the development in replicate 6 was greater than for all others. There was a significant treatment by replicate interaction (P < .05); pGH added during the first 22 h of IVM and pGH added during the second 22 h of IVM in replicate 6 resulted in higher development scores than for controls and continuous pGH addition. However, in replicate 2, continuous pGH resulted in the greatest development. These results suggest that pGH may exert a stimulatory effect on embryo development when present in the IVM media; however, further studies using pGH in IVM culture are necessary. The objectives of the second part of the study were to examine aspects of intracytoplasmic sperm injection (ICSI) using membrane-disrupted spermatozoa, in vitro fertilization (IVF), and sperm-mediated gene transfer in the pig. Porcine oocytes were shipped overnight in maturation media at 39Â°C in a portable incubator. After 22 h of maturation culture, oocytes were washed in maturation medium without gonadotropins and cultured for an additional 22 h. Cumulus cells were removed and oocytes were divided into four treatment groups: treatment 1 = ICSI using membrane-damaged spermatozoa coincubated with linear green fluorescent protein (GFP) DNA; treatment 2 = ICSI using membrane damaged spermatozoa; treatment 3 = IVF with frozen-thawed spermatozoa coincubated with linear GFP DNA prior to IVF; treatment 4 = IVF with frozen-thawed spermatozoa with no DNA coincubation. Embryos were scored for developmental stage at 144 h following fertilization. Each oocyte in the study received a developmental score, based on a scale of 1 = uncleaved, 2 = 2-cell embryo, 3 = 4-cell embryo, 4 = 5- to 8-cell embryo, 5 = 9- to 16-cell embryo, 6 = morula, and 7 = blastocyst. Although no overall difference in development score was observed following the four different treatments, a treatment difference among cleaved oocytes was observed when comparing only the two ICSI treatments (P < .05); development scores were greater in the ICSI treatment in which sperm were not coincubated with linear GFP DNA prior to injection than when the coincubation was performed (3.76 Â± .21 vs. 3.13 Â± .17, respectively). No differences in development score were observed in the two IVF treatments. The percentage of embryos expressing the GFP transgene on d 6 of culture following fertilization was 7.3% in the ICSI+GFP group and 0% in all other treatment groups. Thus, sperm-mediated gene transfer using ICSI in the pig has been demonstrated, although success rates were low.
Master of Science

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Chasles, Manon. „Induction d'une maturation sexuelle précoce chez la chevrette par une exposition prépubertaire au mâle“. Thesis, Tours, 2017. http://www.theses.fr/2017TOUR4044/document.

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Chez les rongeurs, les facteurs sociaux sont connus pour pouvoir moduler la transition pubertaire. Ainsi une jeune souris femelle mise en contact avec un mâle adulte présentera une ouverture vaginale plus précoce qu’une femelle isolée du mâle. L’objectif de ma thèse a été de caractériser les conséquences d’une exposition précoce au mâle dans l’espèce caprine. Les caprins sont une espèce dont la reproduction est saisonnée et permettant, de par sa taille, une étude plus fine des sécrétions endocrines que les rongeurs. Nos résultats ont permis de mettre en évidence que la présence de boucs sexuellement actifs induit une puberté précoce chez les chevrettes, l’ovulation pouvant être induite dès l’âge de 3 mois et demi. Les femelles présentent suite à cette première ovulation une cyclicité régulière ainsi qu’une maturation précoce du tractus génital. Le niveau d’activité sexuelle du bouc est un facteur crucial à l’induction d’une puberté précoce chez la chèvre puisque la présence de mâles castrés n’a aucun effet et que les femelles sont toutes pubères dans le mois suivant l’entrée en saison sexuelle des mâles. Ce travail démontre, dans l’espèce caprine, un rôle crucial de l’environnement social dans la régulation de la maturation sexuelle. Plus particulièrement, cela met en évidence que la présence de boucs peut réactiver efficacement et de manière très précoce l’axe gonadotrope de jeunes chèvres immatures
In rodents, social factors are known to modulate the pubertal transition. Hence, young female mice exposed to adult male exhibit an earlier vaginal opening than young females isolated from male. The aim of my thesis was to characterize the consequences of a precocious exposure to male in another specie, goats. Goats are seasonal breeders and due to their size the fine study of endocrine secretions is easier than in rodents. Our results highlighted that an early exposure to sexually active bucks induces a precocious puberty in young female goats. The first ovulation can be induced as early as 3.5 months old, following this induced first ovulation, goats remain cycling regularly. Females precociously exposed to bucks also exhibit an acceleration of the genital tract maturation. The level of sexual activity of the male is a crucial criteria to induce a precocious puberty in goats as exposure to castrated bucks had no effect on the age at puberty. Moreover, all females exposed to intact bucks ovulated for the first time within a month after buck started to exhibit sexual behaviors. This work revealed, in goats, a crucial role of the social environment on the regulation of sexual maturation. More precisely, it highlights that exposure to bucks is highly efficient to reactivate precociously the gonadotrope axis of youg immature goats

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Mingoti, Gisele Zoccal. „Maturação oocitária associada à esteroidogênese. Papel do soro sanguíneo, albumina sérica e hormônios esteróides“. Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/17/17134/tde-07112001-095400/.

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Este estudo demonstrou que oócitos bovinos são capazes de progredir normalmente a maturação nuclear até a fase de M II quando cultivados in vitro na presença ou ausência de células da granulosa, na presença ou ausência de soro de vaca nas diversas fases do ciclo estral e/ou SFB e na presença de BSA. A progesterona promoveu um retardo na retomada da meiose, mas não impediu que os oócitos atingissem M II, exceto na concentração de 2,5 µg/ml. Além de promover um retardo inicial na retomada da meiose, a testosterona também prejudicou a progressão da meiose até M II. O estradiol também promoveu este retardo inicial, mas isto foi revertido no final da cultura, onde se verificou que quanto maior a concentração de estradiol até a dose de 5,0 µg/ml, maior a porcentagem de oócitos que atingiram M II. Porém, não se observou diferença significativa da porcentagem de oócitos que atingiram M II após maturação no grupo controle (TCM199 com BSA) e nos grupos onde se adicionou estradiol ao meio, em concentrações crescentes. Verificou-se que as células da granulosa e/ou células do cumulus foram capazes de secretar progesterona e estradiol no meio de cultura, quando estimuladas pelo soro bovino, que lhes forneceu precursores (testosterona). As células do cumulus dos COCs cultivados foram capazes de secretar progesterona quando estimuladas por BSA, SFB e estradiol e foram capazes de secretar estradiol quando estimuladas por BSA, progesterona e testosterona. O trabalho demonstrou que a MIV de oócitos bovinos ocorre normalmente na ausência de soro bovino e na ausência de células foliculares e demonstrou que a adição de estradiol não afeta a maturação e é desnecessária, uma vez que as células do cumulus o produzem no meio durante as 24 horas de cultura.
This study has demonstrated that culture medium supplementation with cycling cow serum and/or FCS, granulosa cells or BSA did not affect meiosis progression from GV to M II stage of bovine oocytes matured in vitro. Progesterone impaired meiosis resumption, but it was reverted after 24 hours of culture, except in the concentration of 2,5 µg/ml. Testosterone impaired meiosis resumption and meiosis progression to M II. Estradiol impaired meiosis progression, but it was reverted at the end of the culture, when it was observed that the higher the estradiol concentration in the medium, the higher the number of oocytes reaching M II. However, when IVM of bovine oocytes matured in medium supplemented with only BSA was compared to IVM of bovine oocytes matured in medium supplemented with BSA plus estradiol, no statistical difference was found. Data showed that granulosa cells and/or cumulus cells were able to produce progesterone and estradiol in the culture medium, when stimulated by bovine serum. Cumulus cells were able to produce progesterone when stimulated by BSA, FCS and estradiol and were still able to produce estradiol when stimulated by BSA, progesterone and testosterone. This study has demonstrated that IVM of bovine oocytes can proceed normally in the absence of bovine serum and granulosa cells, and has additionally demonstrated that the medium supplementation with estradiol did not affect nuclear maturation and it is still not necessary, once cumulus cells are able to produce it during the 24 hours of culture.

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Barrero-Monzón, Marinela. „Plasma steroid and vitellogenin concentrations, activity of cathepsins, and egg protein content during oocyte maturation, and influence of hormone injection in four commercial strains of channel catfish Ictalurus punctatus“. Diss., Mississippi State : Mississippi State University, 2005. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.

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Renzi, Adriana. „Análise da influência do hormônio anti-Mülleriano na produção in vitro de embriões bovinos“. Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/17/17135/tde-19042013-154338/.

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A maturação in vitro de oócitos (MIV) é uma importante tecnologia reprodutiva a qual gera oócitos maduros capazes de suportar o desenvolvimento embrionário pré-implantacional e sua completa evolução à termo. Muitos fatores levam ao processo de maturação do oócito, e o AMH (hormônio anti-Mülleriano) tem demonstrado possuir um importante efeito nesta etapa. Neste trabalho nós demonstramos a influência da suplementação de AMH na maturação de complexos cumulus-oócito (COCs). Nossos resultados demonstram que não houve efeito na produção de embriões para COCS grau I. Entretanto, pudemos encontrar diferenças significativas entre os COCs graus II e III maturados na presença de 150ng/ml de AMH. Aqui também demonstramos que não houve diferença significativa na expressão relativa de mRNA para os genes AMHRII e FSHR no oócito, e na expressão relativa de mRNA para os genes AMH, AMHRII e FSHR nas células da granulosa. Nossos resultados corroboram com as importantes funções do AMH na produção de embriões, sugerem que a suplementação do meio de maturação de oócitos com AMH pode ajudar a melhorar a produção de blastocistos.
The in vitro oocyte maturation (MIV) is an important reproductive technology that generates mature oocytes able to support the preimplantation embryonic development and their fully evolution to term. Many factors lead to oocyte maturation process, and the AMH (AntiMüllerian hormone) have demonstrated important effects in the oocyte development. Here, we report the influence of AMH supplementation in the cumulus-oocyte complex (COCs) maturation. We found that AMH had no effect on embryo production of COCs grade I. On the other hand, significant differences between the COCs grade II and COCs grade III matured in AMH 150ng/ml were verified. We have also demonstrated that there were no significant difference in mRNA expression of the genes AMHRII and FSHR in the oocyte, and in mRNA of the genes AMH, AMHRII and FSHR in the granulosa cells. Taken together, the results corroborate the important roles for AMH on embryo production, and suggest that AMH supplementation could achieve successful outcome in the production of blastocysts.

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Vanacker, Charlotte. „Etude du rôle de l’expression du récepteur Neuropiline-1 et de l’exocytose Calcium-dépendante dans le neurone à GnRH sur le développement et la maturation du système à GnRH et la physiologie de la reproduction“. Thesis, Lille 2, 2015. http://www.theses.fr/2015LIL2S038/document.

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L’acquisition de la fertilité chez les mammifères est le résultat d’un long processus de développement et de maturation de l’axe gonadotrope. Cette fonction cruciale à la survie des espèces est orchestrée par une poignée de cellules localisées au niveau de l’aire préoptique hypothalamique chez le rongeur, sécrétant la gonadotropin-releasing hormon (GnRH). La GnRH stimule la sécrétion de LH et de FSH par l’adénohypophyse, qui stimulent à leur tour les gonades. Les cellules à GnRH naissent dans l’épithélium voméronasal pendant le développement embryonnaire et migrent le long des axones voméronasaux pour atteindre l’hypothalamus. A la naissance le système est entièrement en place, toutefois il subira une phase de maturation avant d’atteindre la puberté, signant le début de la fertilité. Chez l’homme, un défaut de sécrétion de GnRH peut conduire à un hypogonadisme hypogonadotrope idiopathique (IHH) caractérisé par une subfertilité et une puberté retardée voire absente, ou même à un syndrome de Kallmann. Dans une grande partie des cas ce défaut de sécrétion est lié à un défaut de développement prénatal et à une diminution du nombre de neurones à GnRH dans dans l’hypothalamus. Depuis peu, la grande famille des semaphorines, déjà connues pour leurs effets chimiotactiques dans certains types cellulaires, et en particulier la semaphorine3A (Sema3A) via son récepteur la Neuropilin-1 (Nrp1), a été décrite comme un facteur indispensable au développement du système à GnRH et décrit comme un « gène Kallmann ». Toutefois son rôle spécifique dans les cellules à GnRH reste à élucider. Le premier objectif de ma thèse a donc été de déterminer le rôle de l’expression du récepteur Nrp1 dans les neurones à GnRH. Le suivi de la maturation sexuelle des animaux Gnrh::cre, Nrp1loxp/loxp (qui n’expriment pas la Nrp1 exclusivement dans les neurones à GnRH) a révélé l’apparition d’une puberté précoce et d’un phénotype de surpoids en comparaison aux animaux contrôles, corrélé à une accumulation des cellules à GnRH dans l’aire préoptique. L’étude de l’embryogenèse du système à GnRH chez ces animaux a démontré une augmentation du nombre de cellules à GnRH pendant leur migration. Nos résultats obtenus in vivo et in vitro suggèrent que la signalisation Nrp1 a un impact sur la survie des neurones à GnRH, et qu’elle module la motilité des cellules en migration et influe leur positionnement dans le cerveau. Le deuxième objectif de ma thèse a été d’étudier le rôle de l’exocytose dépendante du calcium et donc de la neurosécrétion dans les neurones à GnRH sur leur développement. Le suivi de la physiologie d’animaux Gnrh::cre; iBot, dont l’exocytose dépendante du calcium est abolit par clivage de protéine VAMP2/synaptobrevin 2 dans le neurone à GnRH, a révélé l’apparition de deux phénotypes distincts selon la pénétrance du transgène : un groupe ayant une puberté normale et un poids comparable aux animaux contrôles, et un groupe ayant une puberté retardée voire inexistante associé à un surpoids. Ces derniers présentent un IHH, une augmentation du tissu adipeux périgonadique et une hyperleptinémie, alors que la distribution des neurones à GnRH dans le cerveau n’est pas altérée. Ces données mettent en évidence le fait que l’activité de neurosécrétion dans les neurones à GnRH ne serait pas nécessaire pour leur développement embryonnaire, mais qu’elle pourrait jouer un rôle dans le maintien de l’homéostasie énergétique.Ces deux études mettent en avant un lien étroit entre axe gonadotrope et métabolisme énergétique chez les mammifères et ont dévoilés de nouveaux mécanismes qui pourraient être impliqués dans la physiopathologie de la reproduction chez l’homme
Fertility in mammals is the result of a long development and maturation process of the hypothalamic-pituitary-gonadal axis. The reproductive function is orchestrated by a small population of neurons, located in preoptic area of hypothalamus in rodents, and releasing in a pulsatile manner Gonadotropin-releasing hormon (GnRH) in the portal blood vessels, where it is transported to the anterior pituitary gland. GnRH neuropeptide triggers synthesis and release of the gonadotropins LH and FSH, which in turn stimulates development and function of the gonads. GnRH neurons differenciate extracerebraly in the nasal placode and migrate from the vomeronasal organ to the forebrain along olfactory/vomeronasal nerves. At birth, the system is ready, however it will undergo a maturation phase before reaching puberty, signing the beginning of fertility. Deficiency in GnRH release can lead to idiopathic hypogonadotropic hypogonadism (IHH), characterized by a defect in sexual maturation and delayed or no puberty, or even to Kallmann syndrome when the IHH is associated with a deficit in the sens of smell. These phenotypes could be linked to a defect during GnRH neuron migration period and a decrease of GnRH cells located in hypothalamus after birth. Numerous studies have described the influence of different molecules on the migration of GnRH neurons. Recently, the semaphorin family, well known for its chemotactic effects in some cell types, and particularly the semaphorin3A (Sema3A), has been described by our laboratory as an essential factor for the guidance of GnRH neurons during embryogenesis, and characterized as a « Kallmann gene ». However, the role of Sema3A, and its specific receptor Neuropilin-1 (Nrp1) in GnRH neurons remains to be elucidated. The first objective of my thesis was to determine the role of the expression of Nrp1 in GnRH neurons. The analysis of sexual maturation in mice in which Nrp1 expression was selectively knocked out in GnRH neurons revealed a precocious onset of puberty and overweight compared to control littermates, correlated with an accumulation of GnRH neurons in preoptic area. The study of the development of the GnRH system during embryogenesis has shown an increased number of cells during migration. In vivo and in vitro data suggested the involvement of Nrp1 signaling pathway in the survival of GnRH neurons, the control of their motility during migration, and their final positioning in the brain.The second objective of my thesis was to study the role of Calcium-dependent exocytosis, and thus neurosecretion, in GnRH neurons on their development. The monitoring of Gnrh::cre; iBot animals, in which calcium-dependent exocytosis is abolished by cleavage of VAMP2/synaptobrevin2 protein in GnRH neurons, showed the distinction of two different phenotypes. A subpopulation of mice underwent normal puberty onset, with a similar bodyweight than control littermates, and the other one never reached puberty and developed overweight. The later animals exihibited IHH, increase of the volume of perigonadic fat tissue, and hyperleptinemia, with no alteration of GnRH neuron number and distribution. This data established that neurosecretion in GnRH neurons is not a prerequisite for their migration during embryonic development but revealed that it could play an important role in metabolic homeostasis.Together these two studies highlight an intriguing direct connection between GnRH neurons and energy metabolism in mammals as well as new mechanisms that could be implicated in reproductive physiopathology in human

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Sendin, Gaston Carlos. „Maturation of ribbon synapses in hair cells is driven by thyroid hormone“. Doctoral thesis, 2007. http://hdl.handle.net/11858/00-1735-0000-0006-B36B-F.

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„Roles of activin paracrine system in the oocyte maturation of the zebrafish, Danio rerio“. 2001. http://library.cuhk.edu.hk/record=b6073483.

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Pang Yefei.
"August 2001."
Thesis (Ph.D.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (p. 161-197).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Mode of access: World Wide Web.
Abstracts in English and Chinese.

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Assidi, Mourad. „Analyse génomique d'une stimulation FSH des cellules du cumulus au cours de la maturation des ovocytes bovins /“. 2005. http://proquest.umi.com/pqdweb?did=932357981&sid=31&Fmt=2&clientId=9268&RQT=309&VName=PQD.

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Kosinski, Mary E. „Identification of a vesicle budding mechanism for the release of meiotic maturation hormone from Caenorhabditis elegans sperm“. Diss., 2005. http://etd.library.vanderbilt.edu/ETD-db/available/etd-06142005-144021/.

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32

Sendin, Gaston [Verfasser]. „Maturation of ribbon synapses in hair cells is driven by thyroid hormone / submitted by Gaston Carlos Sendin“. 2007. http://d-nb.info/986393363/34.

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Martinez, Daniel Anthony. „Cortical bone growth and maturation in the dwarf rat model induced by recombinant human growth hormone (rhGH)“. 1993. http://catalog.hathitrust.org/api/volumes/oclc/30994431.html.

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Thesis (Ph. D.)--University of Wisconsin--Madison, 1993.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 76-104).

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Wu, Jeng-Ru, und 吳政儒. „Molecular characteristic of oocyte maturation in yellowfin porgy, Acanthopagrus latus -the expression of associated hormone and receptor in brain“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/6qht3h.

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碩士
國立高雄海洋科技大學
水產養殖研究所
103
The aims of this study were to comprehend the roles of Estradiol-17β (E2) in the brain of yellowfin porgy (Acanthopagrus latus) during vitellogenesis and at the final oocyte maturation (FOM). We analyzed the expression levels of brain ERs, CYP19a1b, GnRHs, the expression levels of pituitary FSHβ and LHβ after treated with LHRH-A, E2 and HCG in one-year-old yellowfin porgy during non-spawning season; and examined the egg quality, the distribution of oocytes diameters, the expression levels of ERs, CYP19a1b, GnRHs, FSHβ and LHβ in the brain or pituitary of the matured two-year-old female fish after LHRH-A, HCG, E2 and ATD treatments. According to the results of the study and our previous studies on yellowfin porgy, we speculated that GTHs could stimulate the expression levels of brain ERα, ERβ1, and CYP19a1b may due to binding with the GTH receptors which were presented in the brain, and then E2 which was syntheses in the brain, interacted with ERα and stimulated vitellogenesis. Our study showed that sbGnRH involved of the regulation of FOM of yellowfin porgy. During the FOM, the brain E2 and GTHs simultaneously stimulated the expression of brain ERs; the expression of brain ERα might be involved in the regulation of yolk formation and the FOM; the expressions of brain ERβ1and ERβ2 might also regulate the FOM; the expression of brain GPER might be relate to inhibited GVBD in full-grown stage oocytes. The treatment of HCG combined with E2 in fish could increase the ration of full growth oocyte in ovary, and as the result in increased the amount of ovulated oocyte in following stimulation. Pretreatment of HCG combined with E2, then induced FOM with LHRH-A and decease endogenous E2 at the same time, could improve egg quality and get success in spawning. Our study could provide the application for reproduction of multiple spawning fish, which were low quantity of oocyte in each batch of spawn, and difficult in multiple spawn in artificial environment.

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Smith, Jack Lloyd. „Sexual maturation in sea- and freshwater phases of Pacific salmonids and investigations of reproductive hormone involvement in osmoregulatory adaptation“. Thesis, 1993. http://hdl.handle.net/2429/1132.

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The changes in reproductive parameters and hormones, and blood sodium during the final weeks of sexual maturation in wild coastal salmon, chinook, Oncorhynchus tshawytscha, and steelhead, O. mykiss, were documented for stocks spawning in two similar river systems on the west coast of Vancouver Island, British Columbia, Canada. Chinook were blood-sampled and sacrificed at intervals during migration from the ocean into brackish Nitinat Lake, through the completion of final maturation in Nitinat River, and at the post-spawning stage. Gonadosomatic index (GSI), hepatosomatic index (HSI), and oocyte germinal vesicle stage and hydration level were measured in sacrificed chinook and steelhead. Stamp River steelhead were serially sampled for blood during the month preceding and the month following final maturation. Blood samples were analysed by specific radioimmunoassay for gonadotropin (GtH), estradiol-17β (E₂), testosterone (T), 11-ketotestosterone (11-KT), and 17α,20β-dihydroxyprogesterone (17,20-P). Blood sodium was measured by flame photometry. GSI and hydration level of oocytes increased in females of both species between the earliest stages of maturation and ovulation. Patterns of hormone concentration were similar in chinook and steelhead, but the peaks in concentration of the steroids at each stage were much lower in steelhead. Concentrations of E₂ and T declined from initial levels to ovulation in females, while GtH and 17,20-P increased. In chinook males, T concentration peaked and declined before spermiation, while 11-KT was highest at spermiation, and declined thereafter. The concentration of 11-KT was higher than that of T in steelhead males at spermiation. Little change in GtH and 17,20-P concentration occurred in steelhead males, but these hormones increased in relation to onset of spermiation in chinook. Fertility was compared between chinook and chum salmon, O. keta, maturing in brackish and fresh water. Fertility was low in both brackish and freshwater chinook females at the beginning of the chinook migration, when salinity was high in Nitinat Lake. Blood sodium was higher in brackish water females, but there was no correlation between egg mortality and blood sodium at ovulation. Later in the season, as salinity in net pens decreased, chinook fertility increased. At the beginning of the chum migration season, when salinity was lowest, chinook fertility was equal to that of chum maturing at the same location. The relationship between plasma reproductive hormone concentration and the ability to osmoregulate in sea water was compared in post-spawning steelhead and coho salmon, O. kisutch, transferred from fresh water to brackish holding facilities. All hormones declined to low levels in steelhead while still in fresh water, within 3 weeks of spawning, but persisted at spawning levels for at least 6 weeks in coho. Steelhead blood sodium was stable in the range indicating osmoregulatory adaptation as salinity was increased to full sea water shortly after transfer. Coho blood sodium was higher in 2/3 sea water than that of steelhead in full sea water. High levels of reproductive hormones may interfere with the ability of salmonids to osmoregulate in sea water.

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洪明欣. „The effect of the steroid hormone on ovarian maturation in black tiger shrimp, Penaeus monodon and white shrimp, Litopenaeus vannamei“. Thesis, 2002. http://ndltd.ncl.edu.tw/handle/76919084967201481375.

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碩士
國立海洋大學
水產養殖學系
90
X-organ sinus gland complex, one of the neurosecretory system of crustaceans, secrets GIH (Gonad-inhibiting hormone) to regulate ovary maturation. Unilateral eyestalk ablation has been used to induce an accelerated ovarian maturation and spawning in bloodstocks. The effects of artificial diets supplemented with steroid hormone on the ovarian maturation and spawning in wild and pond shrimps Penaeus monodon, and the ovarian maturation of pond shrimps Litopenaeus vannamei were investigated in this study. Wild eyestalk ablated, shrimps P. monodon were fed with oysters and clams, and eyestalk ablated pond shrimps P. monodon were fed four diets with steroid hormones, [17α-hydroxyprogesterone], [progesterone], [17β-estradiol] and [17α-hydroxyprogesterone, progesterone, 17β-estradiol and testosterone] in experiment 1. Adult shrimps treated with fresh food and diets with four steroid hormones had significantly higher spawning , hatching rate and spawning quantity than fed with the other diets. Wild adult shrimps fed with fresh food had a higher spawning rate and number of egg spent than pond adult shrimps. Pond adult shrimps fed with compound steroid hormone diet had a higher hatching rate than the other treatments. Pond adult P. monodon were divided into five groups of body weight (60g-80g, 80g-100g, 100g-120g, 120g-140g, and 140g-160g) and fed with compound steroid hormone diet in experiment 2. Over 120g of the body weight had significantly higher spawning rate, spawning quantity and hatching rate than the other treatments. Females shrimps over 80g of the body weight had near 200% maturation rate and over 95% hatching rate. 80g of the body weight is the lowest treatment size with the compound steroid hormone diet in this experiment. Female adult pond L. vannamei with a mean body weight of 25g were fed with compound steroid hormone diet and control diet (conducted no steroid hormone) in experiment 3. All the eyestalk ablated shrimps could reach ovarian maturation. However adult pond L. vannamei were fed with compound steroid hormone diet had a fast and a higher ovarian maturation rate. All females without eyestalk ablation had not found ovarian maturation, with compound steroid hormone diet or control diet treatment.

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Vesenbeckh, Silvan M. [Verfasser]. „Studies in mice on the role of the thymic hormone thymulin during early life as a maturational factor for the neuroendocrine system / von Silvan Manuel Vesenbeckh“. 2007. http://d-nb.info/988010062/34.

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Dissertationen zum Thema „Maturation hormonale“

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