Littérature scientifique sur le sujet « Male phenotype »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Sommaire
Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Male phenotype ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Articles de revues sur le sujet "Male phenotype"
1
Goulding, Eugenia H., Sylvia C. Hewitt, Noriko Nakamura, Katherine Hamilton, Kenneth S. Korach et Edward M. Eddy. « Ex3αERKO male infertility phenotype recapitulates the αERKO male phenotype ». Journal of Endocrinology 207, no 3 (10 septembre 2010) : 281–88. http://dx.doi.org/10.1677/joe-10-0290.
Texte intégralRésumé :
Disruption of the Esr1 gene encoding estrogen receptor α (ERα) by insertion of a neomycin resistance gene (neo) into exon 2 (αERKO mice) was shown previously to cause infertility in male mice. While full-length ERα protein was not expressed in αERKO mice, alternative splicing resulted in the low-level expression of a truncated form lacking the N-terminus A/B domain and containing the DNA- and ligand-binding domains. Thus, it was unclear whether the reproductive phenotype in αERKO males was only due to the lack of full-length ERα or was affected by the presence of the variant ERα isoform. The present study examined male mice with deletion of exon 3 of Esr1 gene, lacking the DNA-binding domain, and null for ERα (Ex3αERKO). Dilation of some seminiferous tubules was apparent in male Ex3αERKO mice as early as postnatal day 10 and was pronounced in all tubules from day 20 onward. At 6 weeks of age, sperm numbers and sperm motility were lower in Ex3αERKO mice than in wild-type (WT) mice, and the rete testis and efferent ductules were dilated. Mating studies determined that adult Ex3αERKO males were infertile and failed to produce copulatory plugs. Serum testosterone levels and Hsd17b3 and Cyp17a1 transcript levels were significantly higher, but serum estradiol, progesterone, LH, and FSH levels and Cyp19a1 transcript levels were not significantly different from those in WT mice. These results confirm and extend those seen in other studies on male mice with deletion of exon 3 of Esr1 gene. In addition, the reproductive phenotype of male Ex3αERKO mice recapitulated the phenotype of αERKO mice, strongly suggesting that the αERKO male infertility was not due to the presence of the DNA-binding domain in the truncated form of ERα and that full-length ERα is essential for maintenance of male fertility.
2
Van Gossum, H., T. Robb, M. R. Forbes et L. Rasmussen. « Female-limited polymorphism in a widespread damselfly : morph frequencies, male density, and phenotypic similarity of andromorphs to males ». Canadian Journal of Zoology 86, no 10 (octobre 2008) : 1131–38. http://dx.doi.org/10.1139/z08-091.
Texte intégralRésumé :
In several animal species, one male type coexists with two to several female types, a polymorphism often explained in the context of sexual selection. Where it occurs, one female morph typically resembles the conspecific male phenotype, but the degree of resemblance varies across species. Here, we question whether the degree of phenotypic similarity between male-like females and males varies within species. Phenotypic resemblance is hypothesized to depend on the potential for frequency- and density-dependent selection on male and (or) female phenotypes. We studied six populations of the damselfly Nehalennia irene (Hagen, 1861) that differed widely in estimates of morph frequency and male density. Male-like females resemble males more than another female type resembles males, across populations, when comparisons are based on abdominal patterns. Abdomen phenotype does matter in male–female interactions of damselflies. Furthermore, male-like females were more similar to males at low and high density sites compared with sites with intermediate densities, contrary to the hypothesis that the potential for male harassment influences the degree of phenotypic similarity. Additionally, male-like females of most populations converged on the abdominal phenotype of males of one population rather than on that of syntopic males; a problem that has not received any attention.
3
Zubairi, Mohammad S., Ronald F. Carter et Gabriel M. Ronen. « A Male Phenotype With Aicardi Syndrome ». Journal of Child Neurology 24, no 2 (30 janvier 2009) : 204–7. http://dx.doi.org/10.1177/0883073808322337.
Texte intégral
4
Wagner, Ida Janelle. « TallyHo Diabetic Phenotype Limited to Male Mice ». Plastic and Reconstructive Surgery 129, no 4 (avril 2012) : 727e. http://dx.doi.org/10.1097/prs.0b013e318245eaff.
Texte intégral
5
Tansuğ, Z., Ş. Doran, F. Doran, S. N. Lloyd, U. Erken et R. K. Türkyilmaz. « Intrascrotal Uterus in a Normal Male Phenotype ». European Urology 21, no 2 (1992) : 168. http://dx.doi.org/10.1159/000474827.
Texte intégral
6
Pilastro, Andrea, Jonathan P. Evans, Silvia Sartorelli et Angelo Bisazza. « Male phenotype predicts insemination success in guppies ». Proceedings of the Royal Society of London. Series B : Biological Sciences 269, no 1498 (7 juillet 2002) : 1325–30. http://dx.doi.org/10.1098/rspb.2002.2017.
Texte intégral
7
Wilson, T. A., S. S. Wachtel, S. Howards, J. Lininger et A. Johanson. « H-Y Intermediate Phenotype in Male Pseudohermaphroditism ». Journal of Urology 137, no 4 (avril 1987) : 814. http://dx.doi.org/10.1016/s0022-5347(17)44242-x.
Texte intégral
8
Wilson, Thomas A., Stephen S. Wachtel, Stuart Howards, John Lininger et Ann Johanson. « H-Y intermediate phenotype in male pseudohermaphroditism ». Journal of Pediatrics 109, no 5 (novembre 1986) : 815–19. http://dx.doi.org/10.1016/s0022-3476(86)80699-0.
Texte intégral
9
Fuxjager, Matthew J., Meredith C. Miles et Barney A. Schlinger. « Evolution of the androgen-induced male phenotype ». Journal of Comparative Physiology A 204, no 1 (12 octobre 2017) : 81–92. http://dx.doi.org/10.1007/s00359-017-1215-3.
Texte intégral
10
Mauhin, Wladimir, Abdellah Tebani, Damien Amelin, Lenaig Abily-Donval, Foudil Lamari, Jonathan London, Claire Douillard et al. « Sphingosine-1-Phosphate Levels Are Higher in Male Patients with Non-Classic Fabry Disease ». Journal of Clinical Medicine 11, no 5 (24 février 2022) : 1233. http://dx.doi.org/10.3390/jcm11051233.
Texte intégralRésumé :
Fabry disease is an X-linked lysosomal disease in which defects in the alpha-galactosidase A enzyme activity lead to the ubiquitous accumulation of glycosphingolipids. Whereas the classic disease is characterized by neuropathic pain, progressive renal failure, white matter lesions, cerebral stroke, and hypertrophic cardiomyopathy (HCM), the non-classic phenotype, also known as cardiac variant, is almost exclusively characterized by HCM. Circulating sphingosine-1-phosphate (S1P) has controversially been associated with the Fabry cardiomyopathy. We measured serum S1P levels in 41 patients of the FFABRY cohort. S1P levels were higher in patients with a non-classic phenotype compared to those with a classic phenotype (200.3 [189.6–227.9] vs. 169.4 ng/mL [121.1–203.3], p = 0.02). In a multivariate logistic regression model, elevated S1P concentration remained statistically associated with the non-classic phenotype (OR = 1.03; p < 0.02), and elevated lysoGb3 concentration with the classic phenotype (OR = 0.95; p < 0.03). S1P levels were correlated with interventricular septum thickness (r = 0.46; p = 0.02). In a logistic regression model including S1P serum levels, phenotype, and age, age remained the only variable significantly associated with the risk of HCM (OR = 1.25; p = 0.001). S1P alone was not associated with cardiac hypertrophy but with the cardiac variant. The significantly higher S1P levels in patients with the cardiac variant compared to those with classic Fabry suggest the involvement of distinct pathophysiological pathways in the two phenotypes. S1P dosage could allow the personalization of patient management.
Thèses sur le sujet "Male phenotype"
1
Robertson, Kirsten 1975. « The reproductive phenotype of the male aromatase knockout mouse ». Monash University, Dept. of Biochemistry and Molecular Biology, 2001. http://arrow.monash.edu.au/hdl/1959.1/8444.
Texte intégral
2
Lindsay, Willow Rosella. « Hormonal regulation of male reproductive phenotype in a cooperatively breeding tropical bird ». Pullman, Wash. : Washington State University, 2010. http://www.dissertations.wsu.edu/Dissertations/Spring2010/w_lindsay-042010.pdf.
Texte intégral
3
Jackson, Natasha A. « Disruption of myo-inositol synthesis results in the "classic" Dosophila male sterile phenotype ». Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1603754.
Texte intégralRésumé :
Myo-inositol is a six-carbon sugar alcohol. It is essential as a precursor of the phospholipid membrane component phosphatidylinositol (PI) and the phosphoinositide signaling pathway in all eukaryotes. It aids in cellular metabolism, osmoregulation, and plays an important role in fertilization and diseases such as diabetes, bipolar disorder, and Alzheimer’s disease. Myo-inositol metabolism is comprised of synthesis, transport, catabolism, and recycling. Myo-inositol synthesis is catalyzed by myo-inositol-3-phosphate synthase (MIPS). Surprisingly, synthesis of myo-inositol and its role in fertilization has not yet been studied in the model organism Drosophila melanogaster (fruit fly). We hypothesize that MIPS expression is essential for growth and development of D. melanogaster. In this study, a precise deletion of the entire MIPS gene was generated and confirmed through PCR amplification and sequencing of the resultant DNA fragments. The lack of the MIPS transcript in homozygous MIPS deletion flies was confirmed by RT-PCR. During that experiment, two additional isoforms of MIPS were identified in wild-type flies (CS). Supplementation of chemically defined food with 0.5mM inositol was required to sustain all homozygous MIPS deletion fly strains. Fully-grown homozygous deletion flies could live without additional inositol in the food, but newly emerged larvae only survived to the first instar larval stage. However, even while on rich media supplemented with 170mM inositol, a homozygous MIPS deletion stock was unable to produce viable offspring. Homozygous MIPS deletion strains were identified as male-sterile, incapable of producing offspring when mated to any strain of females (including wild-type). Homozygous female MIPS deletion flies were fertile and maintained a high fecundity rate when mated to any strain (with an exception of homozygous male MIPS deletion flies). The male-sterility was complemented with the addition of a wild-type MIPS gene to chromosome 3. Testes dissections of homozygous male MIPS deletion flies revealed improper progression of spermatogenesis, specifically during sperm individualization. These studies contribute to the understanding of the role of inositol synthesis in growth, development, and fertilization.
4
Coltman, David W. « Phenotype and mating success of male harbour seals, Phoca vitulina, at Sable Island, Nova Scotia ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24770.pdf.
Texte intégral
5
Smith, Joshua. « A Morphological, Functional, and Genetic Investigation of the Male Compound Eye Phenotype of Chrysomya megacephala (Diptera : Calliphoridae)) ». FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/3060.
Texte intégralRésumé :
A very unique compound eye in dipterans is found in males of the forensically important blow fly, Chrysomya megacephala (Diptera: Calliphoridae). This compound eye is characterized by an area of enlarged dorsal facets that, unlike almost all other regional changes in dipteran ommatidia size, is not accompanied by a change in resolution. This region is believed to play a role in mate tracking and allow for increased light capture, though no behavioral studies have tested these claims. An initial goal of the dissertation was to examine the function of this compound eye. Using allometric measurements coupled with behavioral tests, I found larger males had larger eyes and proportionally more dorsally enlarged facets. This finding suggested that larger individuals would move at lower light levels. When comparing similar sized male and females, however, body size and not the specialized male dorsal region dictated the light level at which movement occurred.
A second focus of this dissertation was the development of tools to understand how the male compound eye is genetically regulated. The male-specific enlarged dorsal ommatidia offer a model for understanding how a gross morphological difference of a feature present in both sexes can arise when much of the same genetic content is shared. Since the genes regulating compound eye development are mainly expressed during stages when sex cannot be efficiently determined, I first designed a molecular test for identifying sex by amplifying a region of the transformer gene differentially spliced by sex in blow flies from other genera. Then, I was able to compare temporal patterns of gene expression for rhodopsin genes in separate sexes for the first time in blow flies, which allowed for an initial investigation into the expression patterns influencing the development of the male compound eye.
Apart from the biological significance regarding a unique compound eye, the forensic importance of C. megacephala means that information obtained in this dissertation can be utilized by forensic investigators. The work on low light level movement adds to the understanding of nocturnal oviposition patterns and the ability to sex immature specimens allows for the determination of sex specific development rates.
6
Valle, Andres Rojas. « Gone with the rain : negative effects of rainfall on male reproductive success in a nest-building arachnid ». Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-19092018-153915/.
Texte intégralRésumé :
In nest-building species, offspring survival and reproductive success of parental individuals are strongly influenced by nest location and quality. Thus, quantifying the influence of abiotic conditions on nest integrity is important to predict the effects that weather variability may have on offspring survival and parental reproductive success. Here we investigated how rainfall affects nest integrity and how nest integrity influences male attractiveness and nest tenure. Our study species was the harvestman Quindina limbata, in which males build cup-like mud nests on fallen logs and protect the eggs against predators and fungi infestation. Our dataset is based on 12 months of regular inspections of over 150 nests in a tropical rainforest from Costa Rica. We found that 43% of the nests were destroyed by rainfall. The drag force promoted by rainfall running on the log surface negatively affected nest integrity by decreasing the wall perimeter and the floor area. The intensity of fungi cover was not explained by nest position or by precipitation. No matter the body size of the owner males, nests with high integrity received more eggs than nests with low integrity. Curiously, nests with high values of fungi cover received more eggs. Finally, nest integrity and fungi cover did not affect nest tenure, but the probability of males abandoning their nests increased with time they did not receive eggs. Considering that intense rainfall occurs all year long in tropical forests, the best males can do to decrease the chances of nest destruction is to select protected places to build their nests. Protected sites may keep nest structure better preserved, improve offspring survival, attract more females, and ultimately increase male reproductive successEm espécies que constroem ninhos, a sobrevivência da prole e o sucesso reprodutivo dos indivíduos parentais são fortemente influenciados pela localização e qualidade dos ninhos. Portanto, quantificar a influência das condições abióticas sobre a integridade dos ninhos é importante para prever os efeitos que a variabilidade climática pode ter na sobrevivência da prole e no sucesso reprodutivo dos pais. Neste estudo, investigamos como a chuva influencia a integridade dos ninhos e como a integridade dos ninhos influencia a atratividade masculina e o tempo de posse do ninho. Nossa espécie de estudo foi o opilião Quindina limbata, em que os machos constroem ninhos de barro em troncos caídos e protegem os ovos contra predadores e infestação por fungos. Nosso conjunto de dados é baseado em 12 meses de inspeções regulares de mais de 150 ninhos em uma floresta tropical na Costa Rica. Descobrimos que 43% dos ninhos foram destruídos pela chuva. A força de arrasto promovida pela chuva na superfície dos troncos caídos influenciou negativamente a integridade dos ninhos, diminuindo o perímetro da parede e a área do piso. A intensidade de cobertura de fungos não foi explicada pela posição do ninho ou pela precipitação. O tamanho corporal dos machos não influenciou o ganho de ovos, mas ninhos com alta integridade receberam mais ovos do que ninhos com baixa integridade. Curiosamente, ninhos com altos valores de cobertura de fungos receberam mais ovos. Por fim, a integridade dos ninhos e a cobertura de fungos não influenciaram o tempo de posse do ninho, mas a probabilidade de os machos abandonarem seus ninhos aumentou com o tempo em que não receberam ovos em seus ninhos. Considerando que temporais ocorrem durante todo o ano em florestas tropicais, os melhores machos devem selecionar locais protegidos para construção dos seus ninhos a fim de diminuir as chances de destruição promovida pela chuva. Locais protegidos podem manter a estrutura do ninho melhor preservada, melhorar a sobrevivência da prole, atrair mais fêmeas e, finalmente, aumentar o sucesso reprodutivo dos machos
7
Kwok, Kevin. « Experimental Studies of the Divergence of Pre- and Postcopulatory Phenotypes in Male Drosophila ». Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42123.
Texte intégralRésumé :
ABSTRACT
A major focus in biology is understanding the diversification of life and the processes that cause it. Much of this diversity is in the form of phenotypic variation among populations and species. In this thesis, I investigate two separate aspects of such phenotypic divergence. The first is the divergence of male mate preferences and their potential contribution to precopulatory sexual isolation and speciation. The second is the divergence of postcopulatory phenotypic divergence in the form of seminal fluid protein expression.
With respect to the first aspect, in two separate experiments I investigated the contribution of male mate preferences to sexual isolation between two closely related fruit fly species experiencing differential costs to hybridization, Drosophila recens and Drosophila subquinaria. Male mate preferences are of particular interest because of their potential contribution to sexual isolation, a form of reproductive isolation which can contribute to speciation in sexually reproducing species. In the first experiment, I test for the presence of male mate preferences in each of the two species and whether the relative strength of the preference is concordant with the cost of hybridization. I found that that D. subquinaria males indiscriminately courted both their own (i.e. homospecific) females and heterospecific D. recens females. While D. recens from allopatry showed a similar pattern, those from sympatry courted their own females more than heterospecific females, indicating a pattern of reproductive character displacement. In the second experiment I test the role of learning in the context of these male mate preference in D. recens, and whether learning also showed a pattern of reproductive characteristic. I did not find evidence of learning in that D. recens males did not reduce their courting intensity towards heterospecific females after experiencing rejection by similar females. Consequently, I did not find an indication of reproductive character displacement.
Finally, with respect to postcopulatory phenotypic divergence, I studied differences in seminal fluid protein expression between experimental populations of D. melanogaster experiencing one of three mating environments allowing for differing opportunities of mate competition and the environment in which it took place. These three mating environments include one in which mate competition was absent (MCabsent,), one in which mate competition occurred in a small, structurally simple environment (MCsimple), and one in which mate competition occurred in a larger, somewhat more complex environment (MCcomplex,). Male seminal fluids are of particular interest due to their ability to mediate postcopulatory competition between males and, therefore, can be used to manipulate females to a male’s own fitness benefit, potentially at her expense (i.e. sexual conflict). I investigated divergence in one particular seminal fluid protein implicated in sexual conflict, sex peptide (Acp70A). Whereas, gene expression levels among males from the three-mating treatment did not differ on average, relative stored quantities did, with MCcomplex males carrying significantly less sex peptide than either of MCabsent or MCsimple males (which did not differ from one another). This result suggests that mate competition and the environment in which it occurs play a significant role in the divergence of sex peptide phenotypes.
ABSTRAIT Un objectif majeur de la biologie est de comprendre la diversification de la vie et les processus qui la provoquent. Une grande partie de cette diversité se présente sous la forme de variations phénotypiques entre les populations et les espèces. Dans cette thèse, j'étudie deux aspects distincts d'une telle divergence phénotypique. Le premier est la divergence des préférences des mâles et leurs contributions potentielles à l'isolement sexuel pré-copulatoire et à la spéciation. Le second est la différence de la divergence phénotypique post-copulatoire sous la forme de l'expression des protéines du liquide séminal. En ce qui concerne le premier aspect, dans deux expériences distinctes, j'ai étudié la contribution des préférences de compagnon mâle à l'isolement sexuel entre deux espèces de mouches des fruits étroitement liées subissant des coûts différentiels d'hybridation, Drosophila recens et Drosophila subquinaria. Les préférences des mâles sont particulièrement intéressantes en raison de leurs contributions potentielles à l'isolement sexuel, une forme d'isolement reproductif qui peut contribuer à la spéciation des espèces se reproduisant sexuellement. Dans la première expérience, je teste la présence de préférences de compagnon mâle dans chacune des deux espèces et si la force relative de la préférence est concordante avec le coût de l'hybridation. J'ai constaté que les mâles de D. subquinaria courtisaient sans discernement à la fois leurs propres femelles (c'est-à-dire homospécifiques) et les femelles hétérospécifiques de D. recens. Alors que D. recens de l'allopatrie a montré un modèle similaire, ceux de la sympatrie courtisaient leurs propres femelles plus que les femelles hétérospécifiques, indiquant un modèle de déplacement du caractère reproducteur. Dans la deuxième expérience, je teste le rôle de l'apprentissage dans le contexte de ces préférences de compagnon masculin dans D. recens, et si l'apprentissage a également montré un modèle de caractéristique de reproduction. Je n'ai pas trouvé de preuve d'apprentissage dans la mesure où les mâles D. recens ne réduisaient pas leur intensité de fréquentation envers les femelles hétérospécifiques après avoir été rejetés par des femelles similaires. Par conséquent, je n'ai pas trouvé d'indication de déplacement du caractère reproducteur.
Enfin, en ce qui concerne la divergence phénotypique post-copulatoire, j'ai étudié les différences dans l'expression des protéines du liquide séminal entre les populations expérimentales de D. melanogaster connaissant l'un des trois environnements d'accouplement, permettant différentes possibilités de compétition de compagnon et l'environnement dans lequel elle a eu lieu. Ces trois environnements d'accouplement incluent un environnement dans lequel la compétition entre partenaires était absente (MCabsent,), un dans lequel la compétition entre partenaires se produisait dans un petit environnement structurellement simple (MCsimple) et un dans lequel la compétition entre partenaires se produisait dans un environnement plus grand et un peu plus complexe (MCcomplexe,). Les fluides séminaux mâles sont particulièrement intéressants en raison de leur capacité à négocier la compétition post-copulatoire entre les mâles et, par conséquent, peuvent être utilisés pour manipuler les femelles dans l'intérêt de la forme physique d'un mâle, potentiellement à ses dépens (c'est-à-dire conflit sexuel). J'ai étudié la divergence dans une protéine du liquide séminal particulière impliquée dans un conflit sexuel, le peptide sexuel (Acp70A). Alors que les niveaux d'expression génique chez les mâles du traitement à trois accouplements ne différaient pas en moyenne, les quantités relatives stockées le faisaient, les mâles MCcomplexe portant significativement moins de peptide sexuel que les mâles MCabsent ou MCsimple (qui ne différaient pas les uns des autres). Ce résultat suggère que la compétition de partenaire et l'environnement dans lequel elle se produit jouent un rôle important dans la divergence des phénotypes des peptides sexuels.
8
Magris, Martina. « Phenotypic plasticity in male sexually selected traits in response to social cues ». Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3425756.
Texte intégralRésumé :
Reproductive success of males is strongly influenced by their investment in costly sexually selected traits. Fitness returns, however, are often context-dependent and vary with demographic parameters such as sex ratio and population density. Under conditions of environmental variability, the ability to modulate reproductive decisions on the social context is highly beneficial. As a result, phenotypic plasticity of sexually selected traits is widespread. The aim of my study was threefold. Firstly, I worked to expand our current knowledge on phenotypic plasticity in sexually selected traits both empirically, through a test of the effect of female availability on male mating effort in the nursery web spider, and theoretically, through a literature review on the subject of strategic adjustments of ejaculate quality. Secondly, I evaluated costs and benefits of the anticipatory upregulation of sperm production observed in male guppies as a response to perceived mating opportunities. Finally, I investigated how post-copulatory processes may shape male mate choice. The two species used in my study, the guppy, Poecilia reticulata, and the nursery web spider, Pisaura mirabilis, are particularly suited to investigate phenotypic plasticity of sexually selected traits because they both express costly reproductive traits and they experience environmental fluctuations in socio-sexual factors. When I explored the effect of female availability on male investment in pre- and post-copulatory traits, I found that P. mirabilis males do not respond to variation in this parameter. While males do not reduce their mating effort per partner as mating opportunities increase, they may respond instead by increasing their total reproductive budget. The literature review focusing on plasticity of ejaculate quality, besides showing the diversity of traits subject to adjustment and of stimuli triggering the response, highlighted the difficulty of estimating the fitness consequences of ejaculate plasticity because of the complexity of patterns of co-variation with other reproductive and non-reproductive traits. The experiments investigating costs and benefits of anticipatory ejaculate adjustments showed that the costs of plasticity are minor in guppies, as compared to the costs of phenotype. Furthermore, the trade-off between sperm production and pre-copulatory traits (courtship rate) appears to be stronger than the trade-off between sperm number and quality. Finally, my experiments on post-copulatory processes demonstrated a first male sperm precedence and an advantage of previous partners against novel ones in multiply mated female guppies. These findings brought an important contribution to the understanding of phenomena of male mate choice, such as mate choice copying, audience effect and Coolidge effect. In conclusion, the results of my study demonstrate how trade-offs between pre- and post-copulatory traits have crucial effects on costs and benefits of phenotypic plasticity in reproductive traits, highlighting the importance to adopt an integrative approach and to consider multiple traits and their interaction when studying sexual selection. My results also stress the need for a careful evaluation of episodes of post-copulatory selection when interpreting plasticity of both pre- and post-copulatory investment.Il successo riproduttivo dei maschi è fortemente influenzato dal loro investimento in costosi tratti sottoposti a selezione sessuale. Tuttavia, i vantaggi in termini di fitness di tale investimento sono spesso condizione-dipendenti e variano al variare di parametri demografici quali la sex ratio e la densità di popolazione. In ambienti variabili, l’abilità di adattare le decisioni riproduttive al contesto sociale è altamente vantaggioso. Ne risulta che i tratti selezionati sessualmente sono frequentemente caratterizzati da plasticità fenotipica. L’obiettivo del mio studio era articolato in tre parti. In primo luogo, ho lavorato per espandere l’attuale conoscenza nel campo della plasticità fenotipica di tratti sottoposti a selezione sessuale, sia tramite un approccio sperimentale, testando l’effetto della disponibilità di femmine sullo sforzo riproduttivo di maschi di Pisaura mirabilis, sia tramite un approccio teorico, cioè raccogliendo la letteratura disponibile sul tema degli aggiustamenti strategici della qualità dell’eiaculato. In secondo luogo, ho valutato costi e benefici dell’aumento di produzione spermatica osservato nei maschi di guppy come risposta alla percezione di opportunità di accoppiamento. Infine, ho indagato l’effetto di processi post-copulatori su fenomeni legati alla scelta del partner. Le due specie utilizzate nel mio studio, il guppy, Poecilia reticulata, e il ragno P. mirabilis, sono particolarmente adatti per studiare la plasticità fenotipica di tratti sotto selezione sessuale in quanto entrambi esprimono costosi tratti riproduttivi e subiscono fluttuazioni del loro ambiente socio-sessuale. Lo studio degli effetti della disponibilità di femmine sull’investimento maschile in tratti pre- e post-copulatori ha rivelato che i maschi di P. mirabilis non rispondono a variazioni in questo parametro. Nonostante essi non riducano l’investimento riproduttivo allocato al partner all’aumentare delle opportunità di accoppiarsi, potrebbero invece rispondere aumentando il proprio budget riproduttivo totale. L’esame della letteratura sulla plasticità della qualità dell’eiaculato, oltre a mostrare la varietà dei tratti soggetti ad aggiustamenti e dei fattori di stimolo, ha evidenziato la difficoltà di stimare le conseguenze per la fitness di questo tipo di risposte, a causa della complessità dei pattern di interdipendenza con tratti riproduttivi e non. Gli esperimenti che hanno indagato costi e benefici degli aggiustamenti strategici dell’eiaculato hanno mostrato che in guppy i costi della plasticità sono ridotti, se confrontati con i costi del fenotipo. Inoltre, il trade-off tra produzione spermatica e tratti pre-copulatori (il tasso di corteggiamento) sembra essere più marcato di quello tra numero e qualità degli spermi. Infine, i miei esperimenti sui processi post-copulatori in femmine poliandriche hanno evidenziato una precedenza spermatica del primo maschio e un vantaggio dei partner precedenti rispetto a quelli nuovi. Queste scoperte portano un importante contributo alla comprensione di fenomeni osservati nel contesto della scelta maschile del partner, quali la copia della scelta, l’effetto audience e l’effetto Coolidge. In conclusione, i risultati del mio studio mostrano come i trade-off tra tratti pre- e post-copulatori abbiano importanti effetti sui costi e i benefici della plasticità fenotipica di tratti riproduttivi, evidenziando l’importanza di adottare un approccio integrativo e di considerare vari tratti e la loro interazione nello studio della selezione sessuale. I miei risultati sottolineano anche la necessità di un’attenta valutazione di episodi di selezione post-copulatoria durante l’interpretazione di casi di plasticità nell’investimento sia pre- e che post-copulatorio.
9
Favati, Anna. « Social dominance and personality in male fowl (Gallus gallus domesticus) ». Licentiate thesis, Stockholms universitet, Zoologiska institutionen, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-93019.
Texte intégralRésumé :
Individuals in social species commonly form dominance relationships among each other, and are often observed to differ in behaviour depending on their social status. However, whether such behavioural differences are a consequence of dominance position, or also a cause to it, remains unclear. In this thesis I therefore investigated two perspectives of the relationship between social dominance and personality in the domestic fowl (Gallus gallus domesticus), a social species that forms relatively stable dominance hierarchies. In paper I I investigated the influence of social status on the expression and consistency of behaviours by experimentally changing status between repeated personality assays. The level of vigilance, activity and exploration changed with social status, while boldness and territorial crows appeared as stable individual properties, independent of status. These results showed that social status contribute to both variation and consistency in behavioural responses. Social status should therefore be taken into account when investigating and interpreting variation in personality. In paper II I showed that behaviour in a novel arena test and during encounter with an opponent can predict social status, more specifically that fast exploration and aggressiveness predicted a dominant social position. Together, these results highlight the dynamics of the two-way relationship between social position and individual behaviour and indicate that individual behaviour can both be a cause and a consequence of social status.
10
Mat, Jusoh Hanapi. « Investigation of phenotypic characterisation, metabolic profile and energy balance in male KLF3 knockout mice ». Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/12406.
Texte intégralRésumé :
Obesity is a disease characterised by an excess of white adipose tissue (WAT) driven by increased energy intake and/or decreased energy expenditure. Despite intensive research, the mechanisms underlying energy balance and linking obesity with metabolic disorders are not well understood. The use of genetically modified animal models allows understanding of the involvement of specific genes, such as in fat formation and metabolic processes. This can be used to identify targets for prevention or treatment of obesity. Our laboratory has a particular interest in Krüppel-like factor 3 (KLF3), a transcription factor that is involved in the process of adipocyte maturation. The objective of this study was to investigate the role of KLF3 in energy homeostasis, glucose and lipid metabolism in vivo. For this purpose, Klf3-/- mice on an FVB/NJ strain were developed and bred in-house. Only male Klf3-/- mice were used for investigation, and they were fed a standard chow or lard-based high fat diet. Male Klf3-/- mice have reduced body weight on a chow diet, and were resistant to diet-induced weight gain on a high fat diet. The reduced body weight in Klf3-/- mice was not attributed to reduced food intake, increased energy expenditure or increased faecal energy excretion. Instead, the negative energy balance in Klf3-/- mice was, in part, due to increased glucosuria. Klf3-/- mice have improved glucose tolerance and were resistant to diet-induced glucose intolerance. Klf3-/- mice have increased plasma adipolin levels and increased gene expression associated with anti-inflammatory macrophages in epididymal fat, which may contribute to the improved glucose tolerance. Klf3-/- WAT ex vivo was found to have both increased lipolysis and lipogenesis, implying another potential means of energy loss via futile cycling. In conclusion, KLF3 may play important roles in energy homeostasis and metabolism, and could potentially be targeted for treatments of obesity and associated disorders.
Livres sur le sujet "Male phenotype"
1
West, Michael, et Gabor Linthorst. Fabry Disease. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199972135.003.0049.
Texte intégralRésumé :
Fabry disease was initially believed to be a very rare disorder, but an increase in prevalence following screening studies revealed that it may be more frequent in a less severe (nonclassical) variant. The adult physician can encounter both phenotypes: classical disease arising in childhood, or after establishing the diagnosis in an adult male. The nonclassical phenotype is usually diagnosed after additional investigations in a patient with renal disease or left ventricular hypertrophy (LVH) of unknown origin. Enzyme replacement therapy (ERT) appears to have a modest effect in Fabry disease, and many challenges remain both in understanding the pathophysiology and natural history as well as in improving patient outcomes.
2
Ebstein, Richard P., Songfa Zhong, Robin Chark, Poh San Lai et Soo Hong Chew. Modeling the Genetics of Social Cognition in the Laboratory. Sous la direction de Turhan Canli. Oxford University Press, 2014. http://dx.doi.org/10.1093/oxfordhb/9780199753888.013.017.
Texte intégralRésumé :
This chapter examines recent advances in the genetics of social cognition, discussing evidence from twin studies that confirm the relevancy of genetic hard wiring in understanding many social phenotypes, with important implications for the social sciences and for genome-wide association studies (GWAS) that may identify specific genes contributing to a wide range of social phenotypes, genoeconomics, and individual and social decision making. Stressing the importance of phenotype definition and precise measurement as key to success in GWAS, the authors argue that laboratory-based behavioral economic paradigms using ethnically homogenous student populations generate the best prospects for successful GWAS. Also discussed are the neurochemical/neurogenetic architecture of behavioral economic games that measure individual and social decision making and the considerable progress made in unraveling the neurogenetics of human parenting and the beginning of a political attitudes neuroscience. The authors’ own GWAS is used to present a set of guidelines for future research directions.
3
Maruska, Karen P., et Russell D. Fernald. Social Regulation of Gene Expression in the African Cichlid Fish. Sous la direction de Turhan Canli. Oxford University Press, 2014. http://dx.doi.org/10.1093/oxfordhb/9780199753888.013.012.
Texte intégralRésumé :
How does an animal’s social environment shape its behavior and physiology, and what underlying molecular and genetic mechanisms lead to phenotypic changes? To address this question, the authors used a model system that exhibits socially regulated plastic phenotypes, behavioral complexity, molecular level access, and genomic resources. The African cichlid fishAstatotilapia burtoni, in which male status and reproductive physiology are under social control, has become an important model for studying the mechanisms that regulate complex social behaviors. This chapter reviews what is known about how information from the social environment produces changes in behavior, physiology, and gene expression profiles in the brain and reproductive axis ofA. burtoni. Understanding the mechanisms responsible for translating perception of social cues into molecular change in a model vertebrate is important for identifying selective pressures and evolutionary mechanisms that shape the brain and ultimately result in diverse and complex social behaviors.
4
Brown, Nadia E., et Danielle Casarez Lemi. Sister Style. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780197540572.001.0001.
Texte intégralRésumé :
Sister Style: The Politics of Appearance for Black Women Political Elites centers Black women’s bodies, specifically their hair texture and skin tone, to argue that phenotypic differences among Black women politicians directly impact how they experience political office and how Black voters evaluate them. The book brings together an interdisciplinary, multi-method, and blended epistemological approach of positivism and interpretivism to ask whether African American women’s appearances provide a more nuanced lens through which to study how their raced-gendered identities impact their candidacies and shape their political behavior. The authors take a deep dive into intersectional theory-building, through which they examine the intra-categorical differences among Black women. They find that Black women vary in their political experiences because of their appearances, and that dominant, Eurocentric beauty standards influence the electoral chances of Black women. They observe that skin tone and hair texture, along with the historical legacies that have shaped the current cultural and political contexts, dictate Black women elites’ political experiences and voter evaluations of them. The book asks the following questions: What do the politics of appearance for Black women mean for Black women politicians and for Black voters who evaluate them? What are the origins of the contemporary focus on Black women’s bodies in public life? How do Black women politicians themselves make sense of the politics of appearance? Is there a phenotypic profile into which most Black women politicians fit? What is the effect of variation in Black women’s phenotypes for candidate evaluations? And how do voters process the appearances of Black women candidates?
5
Okasha, Samir. Grafen’s Formal Darwinism, Adaptive Dynamics. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198815082.003.0005.
Texte intégralRésumé :
A core Darwinian idea is that evolution will lead to well-adapted organisms, with phenotypes that maximize their fitness relative to the available alternatives. Grafen’s ‘formal Darwinism project’ attempts to make this idea precise, by explicitly linking the process of natural selection and the optimality of individuals’ phenotypes. Grafen’s analysis ties in closely with the unity-of-purpose constraint on agency, but does not amount to a general vindication of adaptationist assumptions. Under frequencydependence, the theory of adaptive dynamics shows that natural selection does not necessarily lead to phenotypes which maximize fitness conditional on their being fixed in the population. These results suggest that there is no theoretical principle to the effect that natural selection will tend to produce adaptation. The justification for agential thinking in biology must thus be empirical, not theoretical.
6
Franco, Brunella. Oral-facial-digital type 1 syndrome. Sous la direction de Neil Turner. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0319_update_001.
Texte intégralRésumé :
This chapter discusses oral-facial-digital type 1 syndrome (OFD1), which represents a rare syndromic form of inherited renal cystic disease associated with dysfunction of primary cilia. The disease is transmitted as an X-linked dominant male lethal trait. Embryonic lethality in affected hemizygous males is usually reported in the first and second trimesters of pregnancy. The clinical spectrum for this disease includes malformation of the face, oral cavity, and digits with a high degree of phenotypic variability, even within the same family, possibly due to X-inactivation. Renal cystic disease is present in over 65% of adult cases and is usually observed in the second and third decades of life.
7
Thompson, Summer L., et Stephanie C. Dulawa. Pharmacological and Behavioral Rodent Models of OCD. Sous la direction de Christopher Pittenger. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228163.003.0035.
Texte intégralRésumé :
Obsessive-compulsive disorder (OCD) is a severe psychiatric disorder characterized by obsessions and/or compulsions. Only half of patients respond to first-line pharmacological treatments, and symptom relief is typically partial, even in responders. Gaining a better understanding of OCD etiology could lead to better treatments, and potentially to prevention. Animal models are a useful tool for studying neurobiological mechanisms underlying psychiatric phenotypes. Effective use of animal models requires identification of reliable, quantifiable features of the disorder of interest that can be measured across species. The modeled phenotypes then require assessment for predictive validity: the accuracy with which a model makes accurate predictions about the human condition. Once a model has been shown to make accurate predictions, using it to study neurobiological mechanisms is justified. The validity of spontaneous and induced rodent models of OCD is reviewed in this chapter.
8
Brusse, Esther, Pascal Laforêt et Ans T. van der Ploeg. Danon Disease. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199972135.003.0056.
Texte intégralRésumé :
Danon disease, like Pompe disease, is a muscle disorder caused by a primary defect in lysosomal proteins. Danon disease (OMIM #300257) is an X-linked dominant disorder, with males being more severely affected than female carriers. In males, mean disease onset is in their early teens and in females in their late twenties. Clinical hallmarks are a severe cardiomyopathy, muscle weakness, and mild mental retardation. Retinal, liver, and pulmonary disease may also occur. Milder, sometimes isolated cardiac phenotypes without mental retardation are also described. Regular cardiac evaluation, even in asymptomatic patients, is obligatory.
9
Smith-Hicks, C. L., et S. Naidu. Rett Syndrome. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199937837.003.0054.
Texte intégralRésumé :
Rett Syndrome (RTT) is a neurodevelopmental disorder that predominantly affects females but males with RTT have been identified. RTT was first described by an Austrian pediatrician, Andreas Rett. Rett syndrome was mapped to chromosome Xq28 in 1998 and a year later it was determined to be due to mutations in the MeCP2 gene at this locus. Identification of the gene led to the broadening of the clinical phenotype and further characterization into classic and atypical forms of the disease that overlap with Autism spectrum disorders during the period of regression. More than 95% of individuals with classic RTT have mutations in the MeCP2 gene.
10
Joseph, Lisa, Sarah Spence et Audrey Thurm. Autism and Autism Spectrum Disorders : Clinical Overview. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199744312.003.0002.
Texte intégralRésumé :
Autism spectrum disorders (otherwise known as pervasive developmental disorders) are neurodevelopmental conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviors. In order to provide a framework for appreciating the advances that basic science and model systems have made to the field, this chapter will outline the behaviorally defining features of the disorder and describe the phenotype of autism. We will present the current diagnostic conceptualization and criteria for autism spectrum disorders, discuss the diagnostic assessment process, explore frequently co-occurring problems in individuals with autism, and introduce various types of treatments that are frequently employed in this population.
Chapitres de livres sur le sujet "Male phenotype"
1
Wong, Ching Yee Oliver, et Dafang Wu. « Case 98 : Male Breast Carcinoma ». Dans Phenotypic Oncology PET, 323–25. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-09737-9_98.
Texte intégral
2
Park, Jin Ho. « Assessment of Male Sexual Behavior in Mice ». Dans Mood and Anxiety Related Phenotypes in Mice, 357–73. Totowa, NJ : Humana Press, 2011. http://dx.doi.org/10.1007/978-1-61779-313-4_22.
Texte intégral
3
Agbona, Afolabi, Prasad Peteti, Béla Teeken, Olamide Olaosebikan, Abolore Bello, Elizabeth Parkes, Ismail Rabbi, Lukas Mueller, Chiedozie Egesi et Peter Kulakow. « Data Management in Multi-disciplinary African RTB Crop Breeding Programs ». Dans Towards Responsible Plant Data Linkage : Data Challenges for Agricultural Research and Development, 85–103. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-13276-6_5.
Texte intégralRésumé :
AbstractQuality phenotype and genotype data are important for the success of a breeding program. Like most programs, African breeding programs generate large multi-disciplinary phenotypic and genotypic datasets from several locations, that must be carefully managed through the use of an appropriate database management system (DBMS) in order to generate reliable and accurate information for breeding-decisions. A DBMS is essential in data collection, storage, retrieval, validation, curation and analysis in plant breeding programs to enhance the ultimate goal of increasing genetic gain. The International Institute of Tropical Agriculture (IITA), working on the roots, tubers and banana (RTB) crops like cassava, yam, banana and plantain has deployed a FAIR-compliant (Findable, Accessible, Interoperable, Reusable) database; BREEDBASE. The functionalities of this database in data management and analysis have been instrumental in achieving breeding goals. Standard Operating Procedures (SOP) for each breeding process have been developed to allow a cognitive walkthrough for users. This has further helped to increase the usage and enhance the acceptability of the system. The wide acceptability gained among breeders in global cassava research programs has resulted in improvements in the precision and quality of genotype and phenotype data, and subsequent improvement in achievement of breeding program goals. Several innovative gender responsive approaches and initiatives have identified users and their preferences which have informed improved customer and product profiles. A remaining bottleneck is the effective linking of data on preferences and social information of crop users with technical breeding data to make this process more effective.
4
de Kretser, David M., et Liza O’Donnell. « Phenotypic Assessment of Male Fertility Status in Transgenic Animal Models ». Dans Methods in Molecular Biology, 531–48. Totowa, NJ : Humana Press, 2012. http://dx.doi.org/10.1007/978-1-62703-038-0_45.
Texte intégral
5
Kolc, Kristy L., Rikke S. Møller, Lynette G. Sadleir, Ingrid E. Scheffer, Raman Kumar et Jozef Gecz. « PCDH19 Pathogenic Variants in Males : Expanding the Phenotypic Spectrum ». Dans Cell Biology and Translational Medicine, Volume 10, 177–87. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/5584_2020_574.
Texte intégral
6
Brown, Terry R., et Claude J. Migeon. « Androgen Insensitivity Syndromes:Paradox of Phenotypic Feminization with Male Genotype and Normal Testicular Androgen Secretion ». Dans Hormone Resistance and Other Endocrine Paradoxes, 157–203. New York, NY : Springer New York, 1987. http://dx.doi.org/10.1007/978-1-4612-4758-6_6.
Texte intégral
7
Thaler, H., H. Thaler et W. R. Mayr. « Are constitutional factors and/or HLA phenotypes in males predisposing factors for alcoholic cirrhosis ». Dans Trends in Hepatology, 179–82. Dordrecht : Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4904-1_20.
Texte intégral
8
Lucas, Emma S., et Adam J. Watkins. « The Long-Term Effects of the Periconceptional Period on Embryo Epigenetic Profile and Phenotype ; The Paternal Role and His Contribution, and How Males Can Affect Offspring’s Phenotype/Epigenetic Profile ». Dans Periconception in Physiology and Medicine, 137–54. Cham : Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-62414-3_8.
Texte intégral
9
Crossa, José, J. Jesús Cerón-Rojas, Johannes W. R. Martini, Giovanny Covarrubias-Pazaran, Gregorio Alvarado, Fernando H. Toledo et Velu Govindan. « Theory and Practice of Phenotypic and Genomic Selection Indices ». Dans Wheat Improvement, 593–616. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-90673-3_32.
Texte intégralRésumé :
AbstractThe plant net genetic merit is a linear combination of trait breeding values weighted by its respective economic weights whereas a linear selection index (LSI) is a linear combination of phenotypic or genomic estimated breeding values (GEBV) which is used to predict the net genetic merit of candidates for selection. Because economic values are difficult to assign, some authors developed economic weight-free LSI. The economic weights LSI are associated with linear regression theory, while the economic weight-free LSI is associated with canonical correlation theory. Both LSI can be unconstrained or constrained. Constrained LSI imposes restrictions on the expected genetic gain per trait to make some traits change their mean values based on a predetermined level, while the rest of the traits change their values without restriction. This work is geared towards plant breeders and researchers interested in LSI theory and practice in the context of wheat breeding. We provide the phenotypic and genomic unconstrained and constrained LSI, which together cover the theoretical and practical cornerstone of the single-stage LSI theory in plant breeding. Our main goal is to offer researchers a starting point for understanding the core tenets of LSI theory in plant selection.
10
Workman, Paul. « Reflections and Outlook on Targeting HSP90, HSP70 and HSF1 in Cancer : A Personal Perspective ». Dans Advances in Experimental Medicine and Biology, 163–79. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-40204-4_11.
Texte intégralRésumé :
Abstract This personal perspective focuses on small-molecule inhibitors of proteostasis networks in cancer—specifically the discovery and development of chemical probes and drugs acting on the molecular chaperones HSP90 and HSP70, and on the HSF1 stress pathway. Emphasis is on progress made and lessons learned and a future outlook is provided. Highly potent, selective HSP90 inhibitors have proved invaluable in exploring the role of this molecular chaperone family in biology and disease pathology. Clinical activity was observed, especially in non small cell lung cancer and HER2 positive breast cancer. Optimal use of HSP90 inhibitors in oncology will likely require development of creative combination strategies. HSP70 family members have proved technically harder to drug. However, recent progress has been made towards useful chemical tool compounds and these may signpost future clinical drug candidates. The HSF1 stress pathway is strongly validated as a target for cancer therapy. HSF1 itself is a ligandless transcription factor that is extremely challenging to drug directly. HSF1 pathway inhibitors have been identified mostly by phenotypic screening, including a series of bisamides from which a clinical candidate has been identified for treatment of ovarian cancer, multiple myeloma and potentially other cancers.
Actes de conférences sur le sujet "Male phenotype"
1
Unat, Ö. S., M. S. Tasbakan et O. Kacmaz Basoglu. « Positional Obstructive Sleep Apnea : A Mild and Male Predominant Phenotype ». Dans ERS International Congress 2022 abstracts. European Respiratory Society, 2022. http://dx.doi.org/10.1183/13993003.congress-2022.1391.
Texte intégral
2
Braga, Vinícius Lopes, Wladimir Bocca Vieira de Rezende Pinto, Bruno de Mattos Lombardi Badia, José Marcos Vieira de Albuquerque Filho, Igor Braga Farias, Paulo Victor Sgobbi de Souza et Acary Souza Bulle Oliveira. « Spastic paraplegia type 73 : expanding phenotype of the first two Brazilian families ». Dans XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.552.
Texte intégralRésumé :
Context: Hereditary spastic paraplegias (HSPs) represent an expanding group of neurodegenerative diseases characterized mainly by progressive spastic paraparesis of the lower limbs. More than 80 different genetic loci have been associated with HSPs. In 2015, heterozygous pathogenic variants in the CPT1C gene were first associated with SPG73, not yet described in Brazilian patients. Objective: We present clinical, neuroimaging and genetic features of three Brazilian patients with SPG73. Cases reports: We report one male and two female patients, age range 36 to 78 years old. Case 1 presented with a 4-year-history of spasticity, predominantly crural tetraplegia, bladder incontinence, dysphagia and dysphonia. Family history disclosed a sister with epilepsy. Whole-exome sequencing (WES) disclosed a heterozygosis variant c.863G>A (p.Arg288His) in exon 9 of the CPT1C. Cases 2 and 3 are first degree relatives (mother and son). Both presented with long-standing slowly progressive spastic paraplegia. Case 3 presented bladder incontinence, constipation, dysphagia and dysphonia at late stages. Cases 2 and 3 WES disclosed the heterozygosis variant c.196T>G (p.Phe66Val) in exon 4 of the CPT1C. Discussion: Previous literature described six patients from an Italian family with pure HSPs phenotype and the pathogenic variant c.109C>G (p.Arg3. 7Cys) in CPT1C gene. Another group described three patients associated with pure HSPs phenotype and the pathogenic variant (c.226C>T) in the CPT1C gene. All previous reported cases had benign clinical course and bulbar involvement was not described before. One of our cases presented with a de novo variant and rapidly progressive motor and bulbar compromise. Conclusion: our cases expand the current knowledge about SPG73, including a rapidly progressive phenotype with bulbar involvement and cognitive compromise at late stages of disease course.
3
Ximenes, Marcelo Tognato, Isabella Silva Picon, Ivy Liger Riso, Anielle Melina Florencio et Renan Barros Domingues. « Continuous Hemicrania After Clipping of Internal Carotid Aneurism : Case Report ». Dans XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.376.
Texte intégralRésumé :
Context: The trigeminal autonomic cephalalgias (TACs) are primary headaches, however there are some reports of patients with TAC phenotypes related to vascular or neoplastic lesions. We discuss here the case of a patient presenting a headache with a pattern of continuous hemicrania developed after aneurysm clipping surgery. Case report: Male, 37 years old, presented with periodic migraine since childhood, worsening after surgical approach of a ruptured right internal carotid artery aneurysm in 2014. Developed structural epilepsy after the surgical approach. Headache begins in the right occipital region radiating to right hemicranium, of severe intensity, pulsatile, intermittent, lasting 2 hours, partial improvement between crises, with persistence of mild to moderate pain between crises. Exacerbations were accompanied by ocular hyperemia and ipsilateral lacrimation, little improvement with analgesics. Normal neurological examination. Presented total control of the pain after the introduction of indomethacin. Conclusion: Continuous hemicrania is a primary headache with a therapeutic response to indomethacin, classified in the TACs group. Secondary cases may be related to trauma, craniotomy, expansive intracranial injury, among others. The patient presented with these headaches after a surgical approach to clip a ruptured aneurysm. Previous headaches had another pattern. There is a previous report of continuous hemicrania related to an aneurysm of the anterior communicant. This extremely rare case illustrates the importance of testing with indomethacin when this phenotype is present, even in the presence of a triggering factor.
4
Ataei, Abdol Hossain, et Figen Kırkpınar. « Application of In-Ovo Injection of Some Substances for Manipulation of Sex and Improving Performance in Chicken ». Dans International Students Science Congress. Izmir International Guest Student Association, 2021. http://dx.doi.org/10.52460/issc.2021.006.
Texte intégralRésumé :
In intensive production, freshly hatched cockerels are culled in the layer hatchery (7 billion males each year), On the other hand, for meat production rearing female birds has not economic benefits because of male broiler chicks have a faster growth rate and better feed efficiency than females. In this regards several methods are being developed for sex determination in the chick embryo during the incubation period. But these methods need to be rapid, cost-efficient, and suitable practical for commercial use. Additionally, sex determination should be done before pain perception has evolved in chick embryos. Biotechnology by in ovo technique to sex determination of between male and female chicks or sex reversal could improve production and eliminate ethical dilemmas for poultry industries. In birds, the differentiation of embryonic gonads is not determined by genetic gender with the certainty that occurs in mammals and can be affected by early treatment with a steroid hormone. During the development of the chick embryo, the genotype of the zygote determines the nature of the gonads, which then caused male or female phenotype. The differentiation of gonads during the period called the "critical period of sexual differentiation" is accompanied by the beginning of secretion of sexual hormones. Namely, any change in the concentration of steroid hormones during the critical period affects the structure of the gonads. Many synthetic anti-aromatases such as federazole and non-synthetic in plants, mushrooms, and fruits containing natural flavonoids have been used in the experiments in ovo injection of anti-aromatase had no negative effect on the growth performance of sexual reversal female chickens. In conclusion, administration of an aromatase inhibitor causes testicular growth in the genetic female gender, and estrogen administration leads to the production of the left ovotestis in the genetic male gender. Therefore, in the early stages of embryonic development, sexual differentiation can be affected by changing the ratio of sexual hormones. In this review, effects of some substances applied by in ovo injection technique on sex reversal and performance in chicks.
5
Kuhn, M., M. Tschaffon, E. Kempter, A. Ignatius, S. Reber et M. Haffner-Luntzer. « Influence of TH-knockout in CD11b+ myeloid cells on bone and immune phenotype of male mice and its effects on stress-induced pathologies during fracture healing ». Dans III. MuSkITYR Symposium. Georg Thieme Verlag, 2021. http://dx.doi.org/10.1055/s-0041-1736720.
Texte intégral
6
Goveia, Rebeca Mota, Paula Francinete Faustino Silva, Thais Bomfim Teixeira, Isabela Gasparini Arraes, Ruffo Freitas-Júnior et Elisângela Paula Silveira Lacerda. « ANALYSIS OF PATHOGENIC AND UNCERTAIN SIGNIFICANCE VARIANTS IN NINE GENES OF THE BRCA1-MEDIATED HOMOLOGOUS RECOMBINATION PATHWAY IN PATIENTS WITH SUSPECTED HEREDITARY BREAST AND OVARIAN CANCER SYNDROME IN CENTRAL BRAZIL. » Dans Scientifc papers of XXIII Brazilian Breast Congress - 2021. Mastology, 2021. http://dx.doi.org/10.29289/259453942021v31s1038.
Texte intégralRésumé :
Introduction: Breast cancer is the most frequent type of cancer in the world and the biggest cause of female deaths. About 10%–15% of cases are due to hereditary factors. The profile of genetic variants is still scarcely known among the Brazilian population and there are no published data for the central region of the country. Objectives: This study aimed to analyze the profile of pathogenic variants (PV) and of the ones of uncertain significance (VUS) for the RAD50, RAD51C, RAD51D, ATM, PALB2, BRIP1, BARD1 and CHEK2 genes in this population. Methods: 113 patients diagnosed with breast or ovarian cancer who met the National Comprehensive Cancer Networking criteria for hereditary breast and ovarian cancer syndrome were selected. The genes had all regions sequenced using NGS (New Generation Sequencing) and the raw data were evaluated using the Sophia DDM and IonReporter softwares. Results: A total of 3.53% of patients had PV in the PALB2 (c.2257C>T), BARD1 (c.176_177delAG), RAD50 (c.2165dupA) or ATM (c.7913G>A) genes. Patients with pathogenic variants in ATM and PALB2 genes were diagnosed before the age of 40. Patients with pathogenic variants in the BARD1 and RAD50 genes had triple negative breast cancer before the age of 60. The patient with a pathogenic variant in the RAD50 gene also developed ovarian cancer. It was observed that 24.77% of the patients had some VUS, 35.29% of which were in the ATM gene, and a new VUS in the CHEK2 gene (c.1151T>C), related to male breast cancer. Conclusions: These findings contribute to a better understanding of the phenotype of patients with pathogenic variants related to breast cancer in non-BRCA genes. In addition, it reveals a new pathogenic variant in the CHEK2 gene, not described in the literature, related to a case of male breast cancer.
7
Ahmed, Sumaya, et Nasser Rizk. « The Expression of Bile Acid Receptor TGR5 in Adipose Tissue in Diet-Induced Obese Mice ». Dans Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0212.
Texte intégralRésumé :
Bile acids are significant physiological factors for digestion, solubilization, absorption, toxic metabolites and xenobiotics. In addition, bile acids are responsible of signal transduction as well as metabolic regulation that activate several receptors such as farnesoid X receptor (FXR) and the membrane G-protein receptor 5 (TGR5). Activation of TGR5 by bile acids is associated with prevention of obesity as well as ameliorating the resistance to insulin via increasing energy expenditure. The objective of this research is to investigate TGR5 gene expression level in different fat depots including visceral or epididymal adipose tissue (eWAT), brown adipose tissue and inguinal adipose tissue (iWAT) and to study the response of TGR5 gene expression to the antiobesity treatment (SFN). Three groups of male CD1 mice were used in this study; lean group fed with SCD, DIO mice on HFD and DIO obese mice treated with anti-obesity treatment. Body weight (BW) and phenotype data were evaluated by weekly including blood samples for analysis of glucose, insulin, leptin, triglycerides (TG). Total RNA was extracted from different fat depots and RT-PCR profiler array technology was used to in order to assess the mRNA expression of TGR5 and leptin. There was significant downregulation of TGR5 gene expression level in obese (DIO) mice and remarkable upregulation of TGR5 gene expression after successful weight loss in DIO mice treated with SFN in time dependent manner at 1 weeks and 4 weeks of ip applications. In conclusion, obesity is associated with decrease in expression of TGR5 in different fat depots and treatment with anti-obesity drug (Sulforaphane) causes stepwise upregulation of TGR5 gene expression in epididymal white adipose tissue parallel stepwise decrease in body weight. Increase of expression of TGR5 in DIO mice in eWAT is accompanied by improvement in glucose homeostasis and insulin action.
8
Mohammad, A., A. Starastsin et D. Nizheharodava. « THE COMPARISON OF INTRAEPITHELIAL LYMPHOCYTES IN SMALL AND LARGE INTESTINE OF CROHN’S DISEASE PATIENTS ». Dans SAKHAROV READINGS 2021 : ENVIRONMENTAL PROBLEMS OF THE XXI CENTURY. International Sakharov Environmental Institute of Belarusian State University, 2021. http://dx.doi.org/10.46646/sakh-2021-2-79-82.
Texte intégralRésumé :
The changes in intraepithelial lymphocytes phenotype of the small and large intestine were established in patients with Crohn’s disease what may be used as a hallmark of immune inflammation in the gut and make intraepithelial lymphocytes ideal candidate for targeting in further immunoregulation of mucosal adaptive immune response against autoantigens.
9
Gasdaska, Angela, Derek Friend, Rachel Chen, Jason Westra, Matthew Zawistowski, William Lindsey et Nathan Tintle. « Leveraging summary statistics to make inferences about complex phenotypes in large biobanks ». Dans Proceedings of the Pacific Symposium. WORLD SCIENTIFIC, 2018. http://dx.doi.org/10.1142/9789813279827_0036.
Texte intégral
10
Salinas, M., D. Schmidt, R. Lange, M. Libera et S. Ramaswamy. « Computational Prediction of Fluid Induced Stress States in Dynamically Conditioned Engineered Heart Valve Tissues ». Dans ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80787.
Texte intégralRésumé :
There is extensive documented evidence that mechanical conditioning plays a significant role in the development of tissue grown in-vitro for heart valve scaffolds [1–3]. Modern custom made bioreactors have been used to study the mechanobiology of engineered heart valve tissues [1]. Specifically fluid-induced shears stress patterns may play a critical role in up-regulating extracellular matrix secretion by progenitor cell sources such as bone marrow derived stem cells (BMSCs) [2] and increasing the possibility of cell differentiation towards a heart valve phenotype. We hypothesize that specific biomimetic fluid induced shear stress environments, particularly oscillatory shear stress (OSS), have significant effects on BMSCs phenotype and formation rates. As a first step here, we attempt to quantify and delineate the entire 3-D flow field by developing a CFD model to predict the fluid induced shear stress environments on engineered heart valves tissue under quasi-static steady flow and dynamic steady flow conditions.
Rapports d'organisations sur le sujet "Male phenotype"
1
Ostersetzer-Biran, Oren, et Jeffrey Mower. Novel strategies to induce male sterility and restore fertility in Brassicaceae crops. United States Department of Agriculture, janvier 2016. http://dx.doi.org/10.32747/2016.7604267.bard.
Texte intégralRésumé :
Abstract Mitochondria are the site of respiration and numerous other metabolic processes required for plant growth and development. Increased demands for metabolic energy are observed during different stages in the plants life cycle, but are particularly ample during germination and reproductive organ development. These activities are dependent upon the tight regulation of the expression and accumulation of various organellar proteins. Plant mitochondria contain their own genomes (mtDNA), which encode for rRNAs, tRNAs and some mitochondrial proteins. Although all mitochondria have probably evolved from a common alpha-proteobacterial ancestor, notable genomic reorganizations have occurred in the mtDNAs of different eukaryotic lineages. Plant mtDNAs are notably larger and more variable in size (ranging from 70~11,000 kbp in size) than the mrDNAs in higher animals (16~19 kbp). Another unique feature of plant mitochondria includes the presence of both circular and linear DNA fragments, which undergo intra- and intermolecular recombination. DNA-seq data indicate that such recombination events result with diverged mitochondrial genome configurations, even within a single plant species. One common plant phenotype that emerges as a consequence of altered mtDNA configuration is cytoplasmic male sterility CMS (i.e. reduced production of functional pollen). The maternally-inherited male sterility phenotype is highly valuable agriculturally. CMS forces the production of F1 hybrids, particularly in predominantly self-pollinating crops, resulting in enhanced crop growth and productivity through heterosis (i.e. hybrid vigor or outbreeding enhancement). CMS lines have been implemented in some cereal and vegetables, but most crops still lack a CMS system. This work focuses on the analysis of the molecular basis of CMS. We also aim to induce nuclear or organellar induced male-sterility in plants, and to develop a novel approach for fertility restoration. Our work focuses on Brassicaceae, a large family of flowering plants that includes Arabidopsis thaliana, a key model organism in plant sciences, as well as many crops of major economic importance (e.g., broccoli, cauliflower, cabbage, and various seeds for oil production). In spite of the genomic rearrangements in the mtDNAs of plants, the number of genes and the coding sequences are conserved among different mtDNAs in angiosperms (i.e. ~60 genes encoding different tRNAs, rRNAs, ribosomal proteins and subunits of the respiratory system). Yet, in addition to the known genes, plant mtDNAs also harbor numerous ORFs, most of which are not conserved among species and are currently of unknown function. Remarkably, and relevant to our study, CMS in plants is primarily associated with the expression of novel chimericORFs, which likely derive from recombination events within the mtDNAs. Whereas the CMS loci are localized to the mtDNAs, the factors that restore fertility (Rfs) are identified as nuclear-encoded RNA-binding proteins. Interestingly, nearly all of the Rf’s are identified as pentatricopeptide repeat (PPR) proteins, a large family of modular RNA-binding proteins that mediate several aspects of gene expression primarily in plant organelles. In this project we proposed to develop a system to test the ability of mtORFs in plants, which are closely related to known CMS factors. We will induce male fertility in various species of Brassicaceae, and test whether a down-relation in the expression of the recombinantCMS-genes restores fertility, using synthetically designed PPR proteins.
2
Izhar, Shamay, Maureen Hanson et Nurit Firon. Expression of the Mitochondrial Locus Associated with Cytoplasmic Male Sterility in Petunia. United States Department of Agriculture, février 1996. http://dx.doi.org/10.32747/1996.7604933.bard.
Texte intégralRésumé :
The main goal of the proposed research was to continue the mutual investigations into the molecular basis of CMS and male fertility restoration [MRF], with the ultimate goal of understanding these phenomena in higher plants. The experiments focused on: (1) dissecting apart the complex CMS - specific mitochondrial S-Pcf locus, in order to distinguish its essential parts which cause sterility from other parts and study its molecular evolution. (2) Studying the expression of the various regions of the S-Pcf locus in fertile and sterile lines and comparing the structure and ultrastructure of sterile and fertile tissues. (3) Determine whether alteration in respiration is genetically associated with CMS. Our mutual investigations further substantiated the association between the S-Pcf locus and CMS by the findings that the fertile phenotype of a population of unstable petunia somatic hybrids which contain the S-Pcf locus, is due to the presence of multiple muclear fertility restoration genes in this group of progenies. The information obtained by our studies indicate that homologous recombination played a major role in the molecular evolution of the S-Pcf locus and the CMS trait and in the generation of mitochondrial mutations in general. Our data suggest that the CMS cytoplasm evolved by introduction of a urs-s containing sublimon into the main mitochondrial genome via homologous recombination. We have also found that the first mutation detected so far in S-Pcf is a consequence of a homologous recombination mechanism involving part of the cox2 coding sequence. In all the cases studied by us, at the molecular level, we found that fusion of two different cells caused mitochondrial DNA recombination followed by sorting out of a specific mtDNA population or sequences. This sequence of events suggested as a mechanism for the generation of novel mitochondrial genomes and the creation of new traits. The present research also provides data concerning the expression of the recombined and complex CMS-specific S-Pcf locus as compared with the expression of additional mitochondrial proteins as well as comparative histological and ultrastructural studies of CMS and fertile Petunia. Evidence is provided for differential localization of mitochondrially encoded proteins in situ at the tissue level. The similar localization patterns of Pcf and atpA may indicate that Pcf product could interfere with the functioning of the mitochondrial ATPase in a tissue undergoing meiosis and microsporogenesis. Studies of respiration in CMS and fertile Petunia lines indicate that they differe in the partitioning of electron transport through the cytochrome oxidase and alternative oxidase pathways. The data indicate that the electron flux through the two oxidase pathways differs between mitochondria from fertile and sterile Petunia lines at certain redox states of the ubiquinone pool. In summary, extensive data concerning the CMS-specific S-Pcf locus of Petunia at the DNA and protein levels as well as information concerning different biochemical activity in CMS as compared to male fertile lines have been accumulated during the three years of this project. In addition, the involvement of the homologous recombination mechanism in the evolution of mt encoded traits is emphasized.
3
Weiss, David, et Neil Olszewski. Manipulation of GA Levels and GA Signal Transduction in Anthers to Generate Male Sterility. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7580678.bard.
Texte intégralRésumé :
The original objectives of the research were: i. To study the role of GA in anther development, ii. To manipulate GA and/or GA signal transduction levels in the anthers in order to generate male sterility. iii. To characterize the GA signal transduction repressor, SPY. Previous studies have suggested that gibberellins (GAs) are required for normal anther development. In this work, we studied the role of GA in the regulation of anther development in petunia. When plants were treated with the GA-biosynthesis inhibitor paclobutrazol, anther development was arrested. Microscopic analysis of these anthers revealed that paclobutrazol inhibits post-meiotic developmental processes. The treated anthers contained pollen grains but the connective tissue and tapetum cells were degenerated. The expression of the GA-induced gene, GIP, can be used in petunia as a molecular marker to: study GA responses. Analyses of GIP expression during anther development revealed that the gene is induced only after microsporogenesis. This observation further suggests a role for GA in the regulation of post-meiotic processes during petunia anther development. Spy acts as a negative regulator of gibberellin (GA) action in Arabidopsis. We cloned the petunia Spy homologue, PhSPY, and showed that it can complement the spy-3 mutation in Arabidopsis. Overexpression of Spy in transgenic petunia plants affected various GA-regulated processes, including seed germination, shoot elongation, flower initiation, flower development and the expression of a GA- induced gene, GIP. In addition, anther development was inhibited in the transgenic plants following microsporogenesis. The N-terminus of Spy contains tetratricopeptide repeats (TPR). TPR motifs participate in protein-protein interactions, suggesting that Spy is part of a multiprotein complex. To test this hypothesis, we over-expressed the SPY's TPR region without the catalytic domain in transgenic petunia and generated a dominant- negative Spy mutant. The transgenic seeds were able to germinate on paclobutrazol, suggesting an enhanced GA signal. Overexpression of PhSPY in wild type Arabidopsis did not affect plant stature, morphology or flowering time. Consistent with Spy being an O-GlcNAc transferase (OGT), Spy expressed in insect cells was shown to O-GlcNAc modify itself. Consistent with O-GlcNAc modification playing a role in GA signaling, spy mutants had a reduction in the GlcNAc modification of several proteins. After treatment of the GA deficient, gal mutant, with GA3 the GlcNAc modification of proteins of the same size as those affected in spy mutants exhibited a reduction in GlcNAcylation. GA-induced GlcNAcase may be responsible for this de-GlcNAcylation because, treatment of gal with GA rapidly induced an increase in GlcNAcase activity. Several Arabidopsis proteins that interact with the TPR domain of Spy were identified using yeast two-hybrids screens. One of these proteins was GIGANTEA (GI). Consistent with GI and Spy functioning as a complex in the plant the spy-4 was epistatic to gi. These experiments also demonstrated that, in addition to its role in GA signaling, Spy functions in the light signaling pathways controlling hypocotyl elongation and photoperiodic induction of flowering. A second Arabidopsis OGT, SECRET AGENT (SCA), was discovered. Like SPY, SCA O-GlcNAc modifies itself. Although sca mutants do not exhibit dramatic phenotypes, spy/sca double mutants exhibit male and female gamete and embryo lethality, indicating that Spy and SCA have overlapping functions. These results suggest that O-GlcNAc modification is an essential modification in plants that has a role in multiple signaling pathways.
4
Elizur, Abigail, Amir Sagi, Gideon Hulata, Clive Jones et Wayne Knibb. Improving Crustacean Aquaculture Production Efficiencies through Development of Monosex Populations Using Endocrine and Molecular Manipulations. United States Department of Agriculture, juin 2010. http://dx.doi.org/10.32747/2010.7613890.bard.
Texte intégralRésumé :
Background Most of Australian prawn aquaculture production is based on P. monodon. However, the Australian industry is under intense competition from lower priced overseas imports. The availability of all-female monosex populations, by virtue of their large size and associated premium prize, will offer competitive advantage to the industry which desperately needs to counteract competitors within this market. As for the redclaw production in Israel, although it is at its infancy, the growers realized that the production of males is extremely advantageous and that such management strategy will change the economic assumptions and performances of this aquaculture to attract many more growers. Original objectives (as in original proposal) Investigating the sex inheritance mechanism in the tiger prawn. Identification of genes expressed uniquely in the androgenic gland (AG) of prawns and crayfish. The above genes and/or their products will be used to localize the AG in the prawn and manipulate the AG activity in both species. Production of monosex populations through AG manipulation. In the prawn, production of all-female populations and in the crayfish, all-male populations. Achievements In the crayfish, the AG cDNA library was further screened and a third AG specific transcript, designated Cq-AG3, had been identified. Simultaneously the two AG specific genes, which were previously identified, were further characterized. Tissue specificity of one of those genes, termed Cq-AG2, was demonstrated by northern blot hybridization and RNA in-situ hybridization. Bioinformatics prediction, which suggested a 42 amino acid long signal anchor at the N-terminus of the deduced Cq-AG2, was confirmed by immunolocalization of a recombinant protein. Cq-IAG's functionality was demonstrated by dsRNA in-vivo injections to intersex crayfish. Cq-IAGsilencing induced dramatic sex-related alterations, including male feature feminization, reduced sperm production, extensive testicular apoptosis, induction of the vitellogeningene expression and accumulation of yolk proteins in the ovaries. In the prawn, the AG was identified and a cDNA library was created. The putative P. monodonAG hormone encoding gene (Pm-IAG) was identified, isolated and characterized for time of expression and histological localization. Implantation of the AG into prawn post larvae (PL) and juveniles resulted in phenotypic transformation which included the appearance of appendix masculina and enlarged petasma. The transformation however did not result in sex change or the creation of neo males thus the population genetics stage to be executed with Prof. Hulata did not materialized. Repeated AG implantation is currently being trialed. Major conclusions and Implications, both scientific and agricultural Cq-IAG's involvement in male sexual differentiation had been demonstrated and it is strongly suggested that this gene encodes an AG hormone in this crayfish. A thorough screening of the AG cDNA library shows Cq-IAG is the prominent transcript within the library. However, the identification of two additional transcripts hints that Cq-IAG is not the only gene mediating the AG effects. The successful gene silencing of Cq-IAG, if performed at earlier developmental stages, might accomplish full and functional sex reversal which will enable the production of all-male crayfish populations. Pm-IAG is likely to play a similar role in prawns. It is possible that repeated administration of the AG into prawn will lead to the desired full sex reversal, so that WZ neo males, crossed with WZ females can result in WW females, which will form the basis for monosex all-female population.
5
Tucker, Mark L., Shimon Meir, Amnon Lers, Sonia Philosoph-Hadas et Cai-Zhong Jiang. Elucidation of signaling pathways that regulate ethylene-induced leaf and flower abscission of agriculturally important plants. United States Department of Agriculture, janvier 2012. http://dx.doi.org/10.32747/2012.7597929.bard.
Texte intégralRésumé :
The Problem: Abscission is a highly regulated process, occurring as a natural terminal stage of development, in which various organs are separated from the parent plant. In most plant species, the process is initiated by a decrease in active auxin in the abscission zone (AZ) and an increase in ethylene, and may be accelerated by postharvest or environmental stresses. Another potential key regulator in abscission is IDA (Inflorescence Deficient in Abscission), which was identified as an essential peptide signal for floral organ abscission in Arabidopsis. However, information is still lacking regarding the molecular mechanisms integrating all these regulators. In our previous BARD funded research we made substantial progress towards understanding these molecular events in tomato, and the study is still in progress. We established a powerful platform for analysis of genes for regulatory proteins expressed in AZ. We identified changes in gene expression for several transcription factors (TFs) directly linked to ethylene and auxin signaling and several additional regulatory proteins not so obviously linked to these hormones. Moreover, we demonstrated using a virus-induced gene silencing (VIGS) assay that several play a functional role in the onset of abscission. Based on these results we have selected 14 genes for further analysis in stably transformed tomato plants. All 14 genes were suppressed by RNA interference (RNAi) using a constitutive promoter, and 5 of them were also suppressed using an abscission-specific promoter. Transformations are currently at different stages of progress including some lines that already display an abscission phenotype. Objectives: We propose here to (1) complete the functional analysis of the stably transformed tomato plants with T2 lines and perform transcriptome analysis using custom abscission-specific microarrays; (2) conduct an indepth analysis of the role of IDA signaling in tomato leaf and flower abscission; (3) perform transcriptome and proteome analyses to extend the earlier gene expression studies to identify transcripts and proteins that are highly specific to the separation layer (i.e., target cells for cell separation) prior to the onset of abscission; (4) extend and compliment the work in tomato using a winnowed set of genes in soybean. Methodology: Next Generation Sequencing (NGS) of mRNA will be used to further increase the list of abscission-associated genes, and for preparation of a custom tomato abscission microarray to test altered gene expression in transgenic plants. Tandem mass spectrometry (LC-MS/MS) of protein extracts from leaf petiole, flower pedicel and their AZ tissues will be used to identify the proteome of the AZ before and during abscission. AZ-specific gene promoters will be used in stably transformed tomato plants to reduce non-target phenotypes. The bean pod mottle virus (BPMV) plasmid vectors will be used for VIGS analysis in soybean. Expected Contribution: Our study will provide new insights into the regulation of ethylene-induced abscission by further revealing the role of key regulators in the process. This will permit development of novel techniques for manipulating leaf and flower abscission, thereby improving the postharvest performance of agriculturally important crops.
6
Perl-Treves, Rafael, Rebecca Grumet, Nurit Katzir et Jack E. Staub. Ethylene Mediated Regulation of Sex Expression in Cucumis. United States Department of Agriculture, janvier 2005. http://dx.doi.org/10.32747/2005.7586536.bard.
Texte intégralRésumé :
Monoecious species such as melon and cucumber develop separate male and female (or bisexual) flowers on the same plant individual. They display complex genetic and hormonal regulation of sex patterns along the plant. Ethylene is known to play an important role in promoting femaleness and inhibiting male development, but many questions regarding critical sites of ethylene production versus perception, the relationship between ethylene and the sex determining loci, and the possible differences between melon and cucumber in this respect are still open. The general goal of the project was to elucidate the role of ethylene in determining flower sex in Cucumis species, melon and cucumber. The specific Objectives were: 1. Clone and characterize expression patterns of cucumber genes involved in ethylene biosynthesis and perception. 2. Genetic mapping of cloned genes and markers with respect to sex loci in melon and cucumber. 3. Produce and analyze transgenic melons altered in ethylene production or perception. In the course of the project, some modifications/adjustments were made: under Objective 2 (genetic mapping) a set of new mapping populations had to be developed, to allow better detection of polymorphism. Under Objective 3, cucumber transformation systems became available to us and we included this second model species in our plan. The main findings of our study support the pivotal role of ethylene in cucumber and melon sex determination and later stages of reproductive development. Modifying ethylene production resulted in profound alteration of sex patterns in melon: femaleness increased, and also flower maturation and fruit set were enhanced, resulting in earlier, more concentrated fruit yield in the field. Such effect was previously unknown and could have agronomic value. Our results also demonstrate the great importance of ethylene sensitivity in sex expression. Ethylene perception genes are expressed in sex-related patterns, e.g., gynoecious lines express higher levels of receptor-transcripts, and copper treatments that activate the receptor can increase femaleness. Transgenic cucumbers with increased expression of an ethylene receptor showed enhanced femaleness. Melons that expressed a defective receptor produced fewer hermaphrodite flowers and were insensitive to exogenous ethylene. When the expression of defective receptor was restricted to specific floral whorls, we saw that pistils were not inhibited by the blocked perception at the fourth whorl. Such unexpected findings suggest an indirect effect of ethylene on the affected whorl; it also points at interesting differences between melon and cucumber regarding the mode of action of ethylene. Such effects will require further study. Finally, our project also generated and tested a set of novel genetic tools for finer identification of sex determining genes in the two species and for efficient breeding for these characters. Populations that will allow easier linkage analysis of candidate genes with each sex locus were developed. Moreover, effects of modifier genes on the major femaleness trait were resolved. QTL analysis of femaleness and related developmental traits was conducted, and a comprehensive set of Near Isogenic Lines that differ in specific QTLs were prepared and made available for the private and public research. Marker assisted selection (MAS) of femaleness and fruit yield components was directly compared with phenotypic selection in field trials, and the relative efficiency of MAS was demonstrated. Such level of genetic resolution and such advanced tools were not used before to study these traits, that act as primary yield components to determine economic yields of cucurbits. In addition, this project resulted in the establishment of workable transformation procedures in our laboratories and these can be further utilized to study the function of sex-related genes in detail.
7
Lers, Amnon, et Gan Susheng. Study of the regulatory mechanism involved in dark-induced Postharvest leaf senescence. United States Department of Agriculture, janvier 2009. http://dx.doi.org/10.32747/2009.7591734.bard.
Texte intégralRésumé :
Postharvest leaf senescence contributes to quality losses in flowers and leafy vegetables. The general goal of this research project was to investigate the regulatory mechanisms involved in dark-induced leaf senescence. The regulatory system involved in senescence induction and control is highly complex and possibly involves a network of senescence promoting pathways responsible for activation of the senescence-associated genes. Pathways involving different internal signals and environmental factors may have distinctive importance in different leaf senescence systems. Darkness is known to have a role in enhancement of postharvest leaf senescence and for getting an insight into its regulatory mechanism/s we have applied molecular genetics and functional genomics approaches. The original objectives were: 1. Identification of dark-induced SAGs in Arabidopsis using enhancer/promoter trap lines and microarray approaches; 2. Molecular and functional characterization of the identified genes by analyzing their expression and examining the phenotypes in related knockout mutant plants; 3. Initial studies of promoter sequences for selected early dark-induced SAGs. Since genomic studies of senescence, with emphasis on dark-induced senescence, were early-on published which included information on potential regulatory genes we decided to use this new information. This is instead of using the uncharacterized enhancer/promoter trap lines as originally planned. We have also focused on specific relevant genes identified in the two laboratories. Based on the available genomic analyses of leaf senescence 10 candidate genes hypothesized to have a regulatory role in dark-induced senescence were subjected to both expression as well as functional analyses. For most of these genes senescence-specific regulation was confirmed, however, functional analyses using knock-out mutants indicated no consequence to senescence progression. The transcription factor WARK75 was found to be specifically expressed during natural and dark-induced leaf senescence. Functional analysis demonstrated that in detached leaves senescence under darkness was significantly delayed while no phenotypic consequences could be observed on growth and development, including no effect on natural leaf senescence,. Thus, WARKY75 is suggested to have a role in dark-induced senescence, but not in natural senescence. Another regulatory gene identified to have a role in senescence is MKK9 encoding for a Mitogen-Activated Protein Kinase Kinase 9 which is upregulated during senescence in harvested leaves as well as in naturally senescing leaves. MKK9 can specifically phosphorylate another kinase, MPK6. Both knockouts of MKK9 and MPK6 displayed a significantly senescence delay in harvested leaves and possibly function as a phosphorelay that regulates senescence. To our knowledge, this is the first report that clearly demonstrates the involvement of a MAP kinase pathway in senescence. This research not only revealed a new signal transduction pathway, but more important provided significant insights into the regulatory mechanisms underlying senescence in harvested leaves. In an additional line of research we have employed the promoter of the senescence-induced BFN1 gene as a handle for identifying components of the regulatory mechanism. This gene was shown to be activated during darkinduced senescence of detached leaves, as well as natural senescence. This was shown by following protein accumulation and promoter activity which demonstrated that this promoter is activated during dark-induced senescence. Analysis of the promoter established that, at least some of the regulatory sequences reside in an 80 bps long fragment of the promoter. Overall, progress was made in identification of components with a role in dark-induced senescence in this project. Further studies should be done in order to better understand the function of these components and develop approaches for modulating the progress of senescence in crop plants for the benefit of agriculture.
8
Chamovitz, Daniel, et Albrecht Von Arnim. Translational regulation and light signal transduction in plants : the link between eIF3 and the COP9 signalosome. United States Department of Agriculture, novembre 2006. http://dx.doi.org/10.32747/2006.7696515.bard.
Texte intégralRésumé :
The COP9 signalosome (CSN) is an eight-subunit protein complex that is highly conserved among eukaryotes. Genetic analysis of the signalosome in the plant model species Arabidopsis thaliana has shown that the signalosome is a repressor of light dependent seedling development as mutant Arabidopsis seedlings that lack this complex develop in complete darkness as if exposed to light. These mutant plants die following the seedling stage, even when exposed to light, indicating that the COP9 signalosome also has a central role in the regulation of normal photomorphogenic development. The biochemical mode of action of the signalosome and its position in eukaryotic cell signaling pathways is a matter of controversy and ongoing investigation, and recent results place the CSN at the juncture of kinase signaling pathways and ubiquitin-mediated protein degradation. We have shown that one of the many CSN functions may relate to the regulation of translation through the interaction of the CSN with its related complex, eukaryotic initiation factor (eIF3). While we have established a physical connection between eIF3 subunits and CSN subunits, the physiological and developmental significance of this interaction is still unknown. In an effort to understand the biochemical activity of the signalosome, and its role in regulating translation, we originally proposed to dissect the contribution of "h" subunit of eIF3 (eIF3h) along the following specific aims: (i) Isolation and phenotypic characterization of an Arabidopsis loss-of-function allele for eIF3h from insertional mutagenesis libraries; (ii) Creation of designed gain and loss of function alleles for eIF3h on the basis of its nucleocytoplasmic distribution and its yeast-two-hybrid interactions with other eIF3 and signalosome partner proteins; (iii) Determining the contribution of eIF3h and its interaction with the signalosome by expressing specific mutants of eIF3h in the eIF3h- loss-of function background. During the course of the research, these goals were modified to include examining the genetic interaction between csn and eif3h mutations. More importantly, we extended our effort toward the genetic analysis of mutations in the eIF3e subunit, which also interacts with the CSN. Through the course of this research program we have made several critical scientific discoveries, all concerned with the apparent diametrically opposed roles of eIF3h and eIF3e. We showed that: 1) While eIF3e is essential for growth and development, eIF3h is not essential for growth or basal translation; 2) While eIF3e has a negative role in translational regulation, eIF3h is positively required for efficient translation of transcripts with complex 5' UTR sequences; 3) Over-accumulation of eIF3e and loss-of-function of eIF3h both lead to cop phenotypes in dark-grown seedlings. These results were published in one publication (Kim et al., Plant Cell 2004) and in a second manuscript currently in revision for Embo J. Are results have led to a paradigm shift in translation research – eIF3 is now viewed in all systems as a dynamic entity that contains regulatory subuits that affect translational efficiency. In the long-term agronomic outlook, the proposed research has implications that may be far reaching. Many important plant processes, including developmental and physiological responses to light, abiotic stress, photosynthate, and hormones operate in part by modulating protein translation [23, 24, 40, 75]. Translational regulation is slowly coming of age as a mechanism for regulating foreign gene expression in plants, beginning with translational enhancers [84, 85] and more recently, coordinating the expression of multiple transgenes using internal ribosome entry sites. Our contribution to understanding the molecular mode of action of a protein complex as fundamental as eIF3 is likely to lead to advances that will be applicable in the foreseeable future.
9
Samach, Alon, Douglas Cook et Jaime Kigel. Molecular mechanisms of plant reproductive adaptation to aridity gradients. United States Department of Agriculture, janvier 2008. http://dx.doi.org/10.32747/2008.7696513.bard.
Texte intégralRésumé :
Annual plants have developed a range of different mechanisms to avoid flowering (exposure of reproductive organs to the environment) under adverse environmental conditions. Seasonal environmental events such as gradual changes in day length and temperature affect the timing of transition to flowering in many annual and perennial plants. Research in Arabidopsis and additional species suggest that some environmental signals converge on transcriptional regulation of common floral integrators such as FLOWERING LOCUS T (FT). Here we studied environmental induction of flowering in the model legume Medicago truncatula. Similarly to Arabidopsis, the transition to flowering in M. truncatula is hastened by long photoperiods and long periods of vernalization (4°C for 2-3 weeks). Ecotypes collected in Israel retain a vernalization response even though winter temperatures are way above 4°C. Here we show that this species is also highly responsive (flowers earlier) to mild ambient temperatures up to 19°C simulating winter conditions in its natural habitat. Physiological experiments allowed us to time the transition to flowering due to low temperatures, and to compare it to vernalization. We have made use of natural variation, and induced mutants to identify key genes involved in this process, and we provide here data suggesting that an FT gene in M.truncatula is transcriptionally regulated by different environmental cues. Flowering time was found to be correlated with MtFTA and MtFTB expression levels. Mutation in the MtFTA gene showed a late flowering phenotype, while over-expressing MtFTA in Arabidopsis complemented the ft- phenotype. We found that combination of 4°C and 12°C resulted in a synergistic increase in MtFTB expression, while combining 4°C and long photoperiods caused a synergistic increase in MtFTA expression. These results suggest that the two vernalization temperatures work through distinct mechanisms. The early flowering kalil mutant expressed higher levels of MtFTA and not MtFTB suggesting that the KALIL protein represses MtFTA specifically. The desert ecotype Sde Boker flowers earlier in response to short treatments of 8-12oc vernalization and expresses higher levels of MtFTA. This suggests a possible mechanism this desert ecotype developed to flower as fast as possible and finish its growth cycle before the dry period. MtFTA and FT expression are induced by common environmental cues in each species, and expression is repressed under short days. Replacing FT with the MtFTA gene (including regulatory elements) caused high MtFTA expression and early flowering under short days suggesting that the mechanism used to repress flowering under short days has diversified between the two species.The circadian regulated gene, GIGANTEA (GI) encodes a unique protein in Arabidopsis that is involved in flowering mechanism. In this research we characterized how the expression of the M.truncatula GI ortholog is regulated by light and temperature in comparison to its regulation in Arabidopsis. In Arabidopsis GI was found to be involved in temperature compensation to the clock. In addition, GI was found to be involved in mediating the effect of temperature on flowering time. We tested the influence of cold temperature on the MtGI gene in M.truncatula and found correlation between MtGI levels and extended periods of 12°C treatment. MtGI elevation that was found mostly after plants were removed from the cold influence preceded the induction of MtFT expression. This data suggests that MtGI might be involved in 12°C cold perception with respect to flowering in M.truncatula. GI seems to integrate diverse environmental inputs and translates them to the proper physiological and developmental outputs, acting through several different pathways. These research enabled to correlate between temperature and circadian clock in M.truncatula and achieved a better understanding of the flowering mechanism of this species.
10
Horwitz, Benjamin A., et Barbara Gillian Turgeon. Fungal Iron Acquisition, Oxidative Stress and Virulence in the Cochliobolus-maize Interaction. United States Department of Agriculture, mars 2012. http://dx.doi.org/10.32747/2012.7709885.bard.
Texte intégralRésumé :
Our project focused on genes for high affinity iron acquisition in Cochliobolus heterostrophus, a necrotrophic pathogen of maize, and their intertwined relationship to oxidative stress status and virulence of the fungus on the host. An intriguing question was why mutants lacking the nonribosomal peptide synthetase (NRPS) gene (NPS6) responsible for synthesis of the extracellular siderophore, coprogen, are sensitive to oxidative stress. Our overall objective was to understand the mechanistic connection between iron stress and oxidative stress as related to virulence of a plant pathogen to its host. The first objective was to examine the interface where small molecule peptide and reactive oxygen species (ROS) mechanisms overlap. The second objective was to determine if the molecular explanation for common function is common signal transduction pathways. These pathways, built around sensor kinases, response regulators, and transcription factors may link sequestering of iron, production of antioxidants, resistance to oxidative stress, and virulence. We tested these hypotheses by genetic manipulation of the pathogen, virulence assays on the host plant, and by following the expression of key fungal genes. An addition to the original program, made in the first year, was to develop, for fungi, a genetically encoded indicator of redox state based on the commercially available Gfp-based probe pHyper, designed for animal cell biology. We implemented several tools including a genetically encoded indicator of redox state, a procedure to grow iron-depleted plants, and constructed a number of new mutants in regulatory genes. Lack of the major Fe acquisition pathways results in an almost completely avirulent phenotype, showing how critical Fe acquisition is for the pathogen to cause disease. Mutants in conserved signaling pathways have normal ability to regulate NPS6 in response to Fe levels, as do mutants in Lae1 and Vel1, two master regulators of gene expression. Vel1 mutants are sensitive to oxidative stress, and the reason may be underexpression of a catalase gene. In nps6 mutants, CAT3 is also underexpressed, perhaps explaining the sensitivity to oxidative stress. We constructed a deletion mutant for the Fe sensor-regulator SreA and found that it is required for down regulation of NPS6 under Fe-replete conditions. Lack of SreA, though, did not make the fungus over-sensitive to ROS, though the mutant had a slow growth rate. This suggests that overproduction of siderophore under Fe-replete conditions is not very damaging. On the other hand, increasing Fe levels protected nps6 mutants from inhibition by ROS, implying that Fe-catalyzed Fenton reactions are not the main factor in its sensitivity to ROS. We have made some progress in understanding why siderophore mutants are sensitive to oxidative stress, and in doing so, defined some novel regulatory relationships. Catalase genes, which are not directly related to siderophore biosynthesis, are underexpressed in nps6 mutants, suggesting that the siderophore product (with or without bound Fe) may act as a signal. Siderophores, therefore, could be a target for intervention in the field, either by supplying an incorrect signal or blocking a signal normally provided during infection. We already know that nps6 mutants cause smaller lesions and have difficulty establishing invasive growth in the host. Lae1 and Vel1 are the first factors shown to regulate both super virulence conferred by T-toxin, and basic pathogenicity, due to unknown factors. The mutants are also altered in oxidative stress responses, key to success in the infection court, asexual and sexual development, essential for fungal dissemination in the field, aerial hyphal growth, and pigment biosynthesis, essential for survival in the field. Mutants in genes encoding NADPH oxidase (Nox) are compromised in development and virulence. Indeed the triple mutant, which should lack all Nox activity, was nearly avirulent. Again, gene expression experiments provided us with initial evidence that superoxide produced by the fungus may be most important as a signal. Blocking oxidant production by the pathogen may be a way to protect the plant host, in interactions with necrotrophs such as C. heterostrophus which seem to thrive in an oxidant environment.