Thèses sur le sujet « Male phenotype »

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.

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.

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 success
Em 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

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.

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.

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.

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.

Understanding reproductive isolation and divergence is the focus of speciation research. Recent evidence suggested that some Dendroctonus ponderosae populations produced hybrids with reproductive incompatibilities, a reproductive boundary undetected by phylogeographic analyses using molecular markers. Additionally, the unique bifurcated distribution of D. ponderosae and the proposed isolation-by-distance gene flow pattern around the Great Basin Desert provided a unique opportunity to investigate the evolution of postmating (postyzygotic) isolation while also understanding phenotypic divergence along latitudinal (climatic) gradients. First, I characterized the strength, biological pattern, and geographic pattern of postzygotic isolation in D. ponderosae by crossing increasingly divergent populations in a common garden environment. There was little evidence of hybrid inviability in these crosses, yet geographically distant crosses produced sterile males, consistent with expectations under Haldane's rule. Hybrid male sterility appeared at a threshold among increasingly divergent populations, was bidirectional (reciprocal crosses were affected), and less geographically distant crosses did not show significant gender-specific decreases in fitness. Second, a separate investigation of two critical phenotypic traits (body size and development time) was conducted on intrapopulation F2 generation offspring from a common garden experiment. Genetic differences contributing to phenotypic variance were interpreted within the context of the previously described reproductive incompatibilities, gene flow patterns, and latitudinal gradients. Genetic differences in development time were striking between faster developing and more synchronized northern populations and slower developing, less synchronized southern populations. Differences in development time were not detected between populations at similar latitudes. Body size, although more variable than developmental time, generally conformed to expectations, with northern populations being smaller than southern populations. Average adult size was found to be quite different between many populations and did vary between populations at similar latitudes, yet relative sexual size dimorphism was rather consistent. There was no evidence of correspondence between phenotypic traits (body size and development time) and either reproductive boundaries or gene flow patterns. The results suggest that latitudinally imposed climatic differences are likely driving phenotypic divergence between populations.

Les antigènes de groupes sanguins érythrocytaires peuvent être responsables d’une allo-immunisation anti-érythrocytaire et d’accidents immuno-hémolytiques lors de transfusion ou de grossesse. La transfusion des populations d’Afrique sub-saharienne est complexifiée par l’absence d’expression d’antigènes publics, l’expression d’antigènes privés et l’expression d’antigènes partiels en particulier pour le système RH. L’étude des systèmes de groupes sanguins d’intérêt transfusionnel chez les donneurs de Bamako a confirmé l’efficacité de la stratégie du génotypage multiplex incluant des polymorphismes d’appels pour identifier des donneurs rares, qui permet d’accéder aux phénotypes déduits des prélèvements. L’exploration du système RH réalisée par séquençage chez les Dogons et les Peulhs de Mopti met clairement en évidence que la diversité allélique et la fréquence de certains allèles RH sont fonction de l’ethnicité. Un nouvel haplotype associant un allèle RHD*DIVa codant pour un antigène D partiel, des antigènes ce potentiellement partiels, et une réactivité partielle anti-C, a été identifié chez les Dogons. L’exploration des allèles codant pour les antigènes de haute et basse fréquence en Afrique subsaharienne d’Est en Ouest constitue un exemple d’étude qui distingue clairement les populations d’Afrique subsaharienne de celles d’Europe par des différences de fréquences des allèles définissant la diversité génétique d’une population par rapport à une autre. Des orientations stratégiques en fonction du contexte local ont été identifiées pour l’évolution de la transfusion au Mali dans les prochaines années
Blood group antigens may be responsible for alloimmunization and immuno-hemolytic accidents during transfusion or pregnancy. The transfusion of of sub-Saharan Africa populations is complex due to absence of high antigens expression, low antigens expression and partial antigens expression particularly for RH system.The study of blood group for transfusion of interest among donors in Bamako confirmed the effectiveness of multiplex genotyping strategy including polymorphisms calls to identify the rare donors, which permit access to phenotypes derived samples. In a second phase, the exploration of RH blood group system by sequencing among Dogon and Fulani in Mopti clearly shows that the allelic diversity and the frequency of some alleles RH depend on the ethnicity. A new haplotype RHD*DIVa/RHCE*ceTI(D2) combining an RHD*DIVa allele encoding a partial D antigen, potentially partial ce antigens, and a partial reactivity with anti-C, was identified among Dogon. In a third phase, the exploration of alleles encoding of the high and low frequency antigens in sub-Saharan Africa from East to West is an example of a study that clearly makes a difference between the populations of sub-Saharan African and those of Europe in terms of frequencies of alleles that define genetic diversity of one population compared to another. Thus, knowledge of ethnicity is more relevant than knowing the geographical origin in order to optimize transfusion in Saharan Africa and in European countries where some of these populations live. Guidelines strategic in relation with the local context have been identified for development of transfusion for next years in Mali

Background: Obsessive compulsive personality (OCR) characteristics and altered social-emotional processing are central to aetiological and maintenance models of eating disorders (EDs). These characteristics may be associated with genetic risk for EDs. Thesis aim: To examine the gender specificity and familial nature of OCR features and social-emotional processing in EDs. Self-report and behavioural data were collected to test hypotheses. Results: Males with an ED (N = 29) have significant levels of OCR characteristics. They exhibited a rigid and fragmented cognitive style relative to healthy males (N = 42) on behavioural tasks. Men with EDs were not significantly different from healthy males on a measure of visuo-spatial local processing or on social-emotional tasks. As expected, ED offspring of family trios (mean age 21 years) had a detailed, fragmented cognitive style with was some evidence for cognitive inflexibility (N = 73). Mothers of ED offspring (N = 77) had elevated levels of OCR features on self-report measures compared to mothers of healthy offspring (N = 51). On behavioural measures, mothers of ED offspring had relative strengths in local processing and relative difficulties in global processing and spontaneous flexibility. Fathers of ED offspring (N = 60) had higher levels of self-reported obsessive-compulsivity than fathers of HC offspring (N = 56). ED offspring had significant levels of trait and social anxiety. Altered social-emotional processing was associated with a more protracted illness. Mothers and fathers of ED offspring had higher trait and social anxiety than HC parents. There was little evidence for altered attention for social stimuli or difficulties in emotion recognition in parents of ED offspring. OCR and anxious traits were more pronounced in parents who screened positive for a lifetime ED.

L’Alyte accoucheur (Alytes obstetricans) est une espèce d’amphibien où les soins parentaux sont réalisés par le mâle exclusivement. En effet, après l’accouplement, durant lequel le mâle participe activement à l’émission des oeufs, il attache sa ponte autour des articulations de ses membres postérieurs et la porte ainsi pendant tout le développement embryonnaire. Les amphibiens sont très sensibles à l’environnement abiotique, notamment aux conditions hydriques et thermiques. Pour éviter les températures extrêmes, ils peuvent thermoréguler comportementalement, par exemple en sélectionnant des refuges aux conditions microclimatiques favorables. Les Alytes accoucheurs ont montré une sélection de leurs refuges sur la base de leurs propriétés hydriques et thermiques. Les stades de développement précoces sont particulièrement sensibles à la température. Les parents peuvent alors réaliser des comportements parentaux pour en limiter les effets. Un effet phénologique paternel a été observé chez les Alytes accoucheurs, dont les mâles favorisent des températures plus élevées lorsqu’ils portent des oeufs. Les comportements parentaux sont cependant coûteux pour les adultes. Les Alytes accoucheurs ont présenté des performances de locomotion diminuées pendant le port des oeufs, ce qui pourrait induire une diminution de l’aptitude. De plus, les comportements parentaux influencent fortement le développement des jeunes. L’environnement thermique rencontré pendant le stade embryonnaire, et donc pendant la période de soins parentaux chez l’Alyte accoucheur, a eu des effets à court terme et des effets persistants sur la phénologie. L’environnement thermique rencontré pendant le stade larvaire peut également être déterminant. Chez l’Alyte accoucheur, l’environnement thermique postnatal a induit un basculement vers un développement pluriannuel lors d’un développement à 16°C, avec un hivernage au stade têtard, alors qu’il a été annuel lors d’un développement à 20°C et 24°C. L’environnement thermique postnatal a également impliqué des modifications morphologiques, physiologiques et comportementales. Enfin, une implication de la physiologie, et notamment de la fréquence cardiaque, a été observée tout au long du développement embryonnaire et larvaire des jeunes
The common Midwife toad (Alytes obstetricans) is a species of amphibian in which parental care is performed exclusively by the male. Indeed, after mating, during which the male actively helps the female for the emission of the eggs, he attaches the clutch around the joints of his hind limbs and thus carries it throughout embryonic development. Amphibians are very sensitive to the abiotic environment, especially to hydric and thermal conditions. To avoid extreme temperatures, they can behaviourally thermoregulate, for example by selecting refuges with favourable microclimatic conditions. The common Midwife toad has shown a selection of their refuges based on their hydric and thermal properties. The early stages of development are particularly sensitive to temperature. Parents can then carry out parental care to limit the effects. A paternal phenological effect has been observed in common Midwife toad, whose males favour higher temperatures when they carry eggs. Parental care is costly for adults, however. The common Midwife toad exhibited decreased locomotion performances during egg carrying, which could lead to decreased fitness. In addition, parental care strongly influences the development of young. The thermal environment encountered during the embryonic stage, and therefore during the period of parental care in the common Midwife toad, had both short-term and persistent effects on the phenology. The thermal environment encountered during the larval stage can also be decisive. In the common Midwife toad, the postnatal thermal environment induced a switch to multi-year development during development at 16 ° C, with overwintering at the tadpole stage, whereas it was annual during development at 20 ° C and 24 ° C. The postnatal thermal environment has also involved morphological, physiological, and behavioural changes. Finally, an involvement of physiology, and in particular heart rate, has been observed throughout the embryonic and larval development of the young

Les perturbateurs endocriniens (PE) sont des composés synthétiques capables de se lier aux récepteurs cellulaires et d'imiter ou de bloquer le fonctionnement des hormones naturelles, pouvant ainsi entraîner des effets néfastes sur la santé. Ces dernières années, des hypothèses ont été émises selon lesquelles les PE pourraient également contribuer au développement de maladies allergiques et respiratoires. En outre, il est probable que les PE pourraient déjà agir pendant la grossesse en provoquant un diabète gestationnel (DG) et une hypertension induite par la grossesse, pouvant également provoquer une hypertension et un diabète plus tard dans la vie. Ce travail de thèse a permis de mettre en évidence que l'exposition maternelle aux phtalates et aux métaux lourds (plomb, cadmium et manganèse) pendant la grossesse pourrait être associée au diabète gestationnel, à l'hypertension induite par la grossesse et à l'eczéma/dermatite atopique chez l'enfant. Nous avons utilisé les données de la cohorte Française de naissance mère-enfant, EDEN (Étude des déterminants pré et post-natals du développement de la santé de l’enfant) pour examiner les hypothèses de ce travail de thèse. Nos résultats apportent de nouvelles preuves potentielles sur la relation entre les perturbateurs endocriniens (phtalates et métaux lourds étudiés) et la santé de la mère et de l’enfant, selon lesquelles l’exposition prénatale à certains phtalates et métaux toxiques lourds pourrait jouer un rôle dans le développement du diabète gestationnel et de l’hypertension induite par la grossesse pendant la grossesse et, ultérieurement, un eczéma pendant la petite enfance
All humans are exposed to chemicals in everyday life, from food, indoor environment, cosmetics and other products that surround us at home and at work. Endocrine disruptors (EDCs) are man-made compounds that can bind to cell receptors and mimic or block the functions of natural hormones potentially resulting in adverse health effects. In recent years, hypotheses have been put forward that EDCs may contribute also to the development of allergic and respiratory diseases. In addition, it is likely that EDCs could act already during pregnancy by causing gestational diabetes mellitus and pregnancy induced hypertension, which may also trigger to develop hypertension and diabetes mellitus later in life. This dissertation provides evidence that maternal exposure to phthalates and heavy metals (Lead, Cadmium and Manganese) during pregnancy may be associated with gestational diabetes mellitus, pregnancy induced hypertension and later eczema/atopic dermatitis in children. We used ongoing French EDEN-mother child cohort data for our three studies. Our results add new suggestive evidence on the relationship between EDCs (phthalates and heavy metals we studied) and maternal and children health, that prenatal exposure to certain phthalates and heavy toxic metals may play a role in the development of gestational diabetes mellitus and pregnancy induced hypertension during pregnancy and later eczema in early childhood. Future research focusing on larger populations and addressing multiple exposures assessed prenatally and postnatally are required to provide more evidence on possible contributions of emerging pollutants to study the role of phthalates and heavy metals

Chez les plantes à fleurs, la gynodioécie -- système dans lequel coexistent des individus femelles et des individus hermaphrodites -- est le système de reproduction le plus commun après l'hermaphrodisme. La question de l'évolution et surtout du maintien de la gynodioécie et du polymorphisme génétique sous-jacent a intrigué les chercheurs depuis le 19e siecle. Aujourd'hui, les grands principes de son évolution sont posés mais beaucoup de zones d'ombres persistent. Durant ma thèse, j'ai exploré trois aspects de la gynodioécie en utilisant une approche expérimentale chez l'espèce Silene nutans et une approche théorique. Je me suis en premier lieu intéressée au déterminisme génétique de la gynodioécie grâce à la réalisation de croisements contrôlés qui m'ont permis de montrer que le déterminisme génétique du sexe était cytonucléaire, c'est à dire contrôlé par plusieurs gènes de stérilité mâle cytoplasmique (CMS) et plusieurs restaurateurs nucléaires de fertilité. En parallèle, j'ai porté une attention particulière aux plantes gynomonoïques -- celles où coexistent sur le même pied des fleurs pistillés (femelles) et des fleurs parfaites (hermaphrodites) -- fréquentes chez Silene nutans comme chez d'autres espèces gynodioïques. J'ai montré que les caractéristiques reproductrices et florales de ce troisième phénotype sexuel étaient souvent intermédiaires entre celles des femelles et des hermaphrodites mais pouvaient dépendre de la proportion de fleurs pistillées sur la plante. Par ailleurs et contrairement à ce qui avait été suggéré, la plasticité du phénotype gynomonoïque s'est révélée être relativement réduite, suggérant un déterminisme génétique dont la caractérisation est encore en cours. La troisième partie de ma thèse a été motivée par les preuves récentes d'hétéroplasmie -- coexistence de différents génomes mitochondriaux au sein d'un individu -- et de la transmission occasionnelle du génome mitochondrial par le pollen chez Silene vulgaris. J'ai montré théoriquement que la présence d'un gène de stérilité mâle cytoplasmique favorisait l'évolution de la fuite paternelle de mitochondries. J'ai également vérifié expérimentalement l'hérédité mitochondriale chez Silene nutans par le génotypage des descendances de croisements contrôlés.

acase@tulane.edu
Anthropogenic noise is an evolutionarily recent phenomenon and many animals respond by changing the pitch and timing of their vocalizations to avoid masking. A benefit to modifying a vocal mating signal in the context of noise is increased transmission distance. This same modification may pose a fitness cost if that signal feature is also sexually selected. Bird song is a well-studied sexual signal used in territory defense and mate attraction. Physically difficult to produce components of song are thought to be honest signals of male quality. One such trait is a male's ability to maximize the rate of note production at a given frequency bandwidth; this tradeoff is known as vocal performance. Studies have shown modifications to song in the context of noise, specifically to trill rate and bandwidth. Costs of these modifications may include increased conflict with neighboring males, which could potentially lead to decreased body condition, loss of a territory, or less time spent attracting a female. Few studies have investigated this tradeoff between environmentally induced selection (i.e. natural selection) and social selection (i.e. sexual selection) on song in an urban landscape. Therefore, a gap remains in our knowledge of the consequences on fitness of urban song adaptation for signalers. Using the white-crowned sparrow (Zonotrichia leucophrys) in the San Francisco Bay Area of California, the objectives of my dissertation research include 1) testing if vocal performance is a salient signal for white-crowned sparrows, 2) testing if receivers are responding specifically to variation in trill rate or bandwidth, and 3) testing the effect of ambient noise level on receiver assessment of vocal performance. Overall, my dissertation research suggests that both anthropogenic and natural soundscapes shape the evolution of song and receiver behavior. Modifications to song structure that increase signal detection come at the cost of decreased signal salience for male competitors. Additionally, anthropogenic noise appears to change how males utilize vocal performance. Therefore, species living in noisy areas may face consequences of decreased fitness over time due to masked honest signals and increased male-male conflict.
1
Jennifer N. Phillips

Research Doctorate - Doctor of Philosophy (PhD)
The impact of exposure to environmental hazards on personal health and the health of our offspring has become of great importance over recent decades. The effect of gestational exposures across generations have been widely investigated, but what is less well understood is the impact of paternal preconception exposure. The research presented utilised the environmental hazard, acrylamide as a model to facilitate a greater understanding of paternal preconception exposure, and the multi- and transgenerational consequences. Throughout this research, the effect of acrylamide on the male reproductive tract was investigated, following single and multigenerational exposures, and the importance of the enzyme CYP2E1, known to modulate acrylamide-toxicity. CYP2E1 is a P450 metabolising enzyme, localised to the endoplasmic reticulum and/or the mitochondria throughout various tissues of the body, including in the pachytene spermatocytes of the testis and epithelial cells of the epididymis within the male reproductive tract. It was hypothesised that acrylamide would alter CYP2E1 protein abundance and DNA fragmentation in the male reproductive tract, and multigenerational exposure of the male germline would result in altered phenotypes in progeny. An in vivo acute exposure model and in vitro cell culture were utilised to establish the effect of acrylamide on CYP2E1 in the male reproductive tract. Prior to the examination of acrylamide exposures, we performed immunoblotting analysis of CYP2E1 and optimisation of subcellular fractionation techniques to isolate and purify the components of the cell that harbour CYP2E1. Mitochondrial fractions from liver tissue were extracted and purified, while microsomal fractions from the endoplasmic reticulum require further optimisation, and thus this technique was not utilised for further analyses. From the in vivo and in vitro exposure regimes it was determined that acrylamide increased the abundance of CYP2E1 in the spermatocytes of the testis (150% of vehicle) and mECap18 cells (130% of vehicle) and elevated DNA fragmentation in both the mECap18 cells (120% of vehicle) and mature spermatozoa (≥120% of vehicle). To postulate potential mechanisms of this induction comparison to the well-characterised CYP2E1 substrate ethanol was performed. Ethanol exposure also elevated CYP2E1 abundance in spermatocytes (130% of vehicle) and the mECap18 cells (150% of vehicle), in addition to Cyp2e1 transcript expression in the mECap18 cells only (≤500% of vehicle). To model environmental multigenerational exposure, a chronic regime of acrylamide exposure at a human-relevant dose following the paternal germline was employed. Paternal and grand-paternal acrylamide exposure modified the response to acrylamide in male offspring with significantly altered DNA fragmentation in mature spermatozoa and CYP2E1 abundance in spermatocytes with or without acrylamide exposure of the progeny. Additionally, acrylamide exposure at the human-relevant dose of ≈0.2 mg/kg bw/day resulted in the transgenerational phenotype of decreased testis to body weight ratio in the male F2 progeny following ancestral exposure to acrylamide (75-80% of unexposed lineage). The experiments outlined herein demonstrate novel understanding of acrylamide and its effects on the male reproductive tract, and the impact of preconception exposure to the reproductive health of multiple generations. These data provide new insight into the transgenerational impact of an environmental hazard at under a human-relevant regime, following paternal preconception exposure, to expand our understanding of environmental health.

The anteroventral periventricular nucleus (AVPV) of the preoptic area mediates the positive feedback effects of estradiol (E2) on LH surge in rats. Consistent with their role in female reproduction, the neurons in this region are more numerous in adult females than males. This sex difference is established due to E2-mediated cell death in the developing male AVPV. Loss of neurons in the AVPV permanently abolishes the ability of E2 to trigger LH surge release. However, the identity of the neurons lost during AVPV masculinization and the mechanism underlying E2-triggered cell death have not been clearly defined to date. This dissertation shows that, developmental exposure to E2 permanently reduces the number of dual-phenotype GABAergic/Glutamatergic (GABA/Glu) neurons, supporting the role of these neurons in female-specific LH surge release. My results identified a key role for TNFα-activated NFκB-mediated cell survival in establishing sex differences in the GABA/Glu population in the AVPV. GABAergic neurons in males had higher levels of TRAF Interacting Protein (TRIP), an inhibitor of the NFκB pathway. Thus, the male AVPV had lower levels of nuclear NFκB and its downstream target, pro-survival Bcl-2 mRNA than females. I also showed that E2 produces these sex differences by upregulating TRIP gene expression and thus reduces the number of GABA/Glu neurons in the male AVPV. Using the N42 GABA/Glu cell line as an in vitro model for the AVPV, I verified that E2 reversed TNFα-mediated effects on NFκB activation, Bcl-2 mRNA, and caspase activity. Moreover, E2 could directly upregulate TRIP mRNA levels, only in the presence of TNFα. To understand the nature of this cooperativity, I cloned the proximal TRIP promoter, identified an ERE half-site and a novel TNFRE in a region 1000 base pairs upstream of the transcription start site. Mutation of either of these sites abolished the stimulatory effect of E2 on promoter activity, suggesting that cooperative action of E2 and TNFα is required for TRIP promoter activation. To summarize, these studies provide a novel mechanism for sexual differentiation of the AVPV in which E2 acts cooperatively with TNFα to inhibit a neuroprotective pathway in GABA/Glu neurons of the male AVPV.

No
We report here the genome sequence of an ancient human. Obtained from approximately 4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20x, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.

碩士
國立屏東科技大學
熱帶農業暨國際合作研究所
91
Under different temperature regime (30/25℃, 28/20℃, 25/18℃, 20/18℃, 20/12℃; day/night), gene-cytoplasmic male sterility ‘Acc. 195’ plants had greater vegetative growth than that of its normal maintainer lines. Except for the carotenoid contain, plant height, internode length, leaf area, and chlorophyll contain except for the carotenoid contain in the CMS plant were significantly larger than the normal plant. ‘Acc. 14’ and ‘Acc. 17’ plants under 28/20℃ day/night treatment showed abundant growth than their own normal isogenic maintainer. However, under 25/18℃ day/night temperature regime ‘Acc. 17’ plant could set fruits and its anther could produce normal viable pollen grains with numbers showed no significant difference to those of normal maintainer line. There was also no significant difference in plant growth character between the recovered ‘Acc. 17’ plants and its normal maintainer plants. ‘Acc. 17’ plants treated seedling established in summer and treated with 25/18℃ day/night temperature regime at anthesis of the first branch, the recovering fertility temperature regime only react on branch with non-visible bud and make the original male sterile plant fertile. According to cytological microsporogenesis observation recovering temperature regime must be present in archesporial cell stage or the earlier primordial stamen differentiation stage. When under 28/20℃, anther showed the degeneration delaying and vacuolate tapetum encroaching on the tetrad caused the collapes of developing microspores. While in that under 25/18℃, tapetum developed normally and the microspores could release from tetrad to form normal pollen grains. Analysis on the expression of male fertility in different ‘Acc. 17’ generations indicated that: The expression of male sterility of F1 generation and BC1F1 generation were unstable and related to the air temperature regime about twenty days before the anthesis of pepper flower. Cool air temperature regime (25/18℃) increased the expression of male fertility; while hot air temperature regime (28/20℃) caused plants to be sterile. Nevertheless, ‘Acc. 17’ F2 generation showed segregation of total male fertile, total male sterile and unstable male sterile (fertile) plants which fit χ2 ratio of 9：3：4. It assumed that the genetic control of the unstable sterility (fertility) was by two major epistasis recessive genes.