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1
Harbison, Diane T. "Male-specific transcripts from Drosophila melanogaster." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337508.
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Bentley, Joanna Kate. "The interaction between male-killing spiroplasma and 'Drosophila'." Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409219.
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Walker, Michael John. "Proteins of the male accessory gland of Drosophila melanogaster." Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485188.
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In Drosophila melanogaster, the male seminal fluid contains proteins that are important for reproductive success. Many of these proteins are synthesised by the male accessory glands and are secreted into the accessory gland lumen, where they are stored until required. Previous studies on the identification of Drosophila accessory gland' proteins have largely focused on characterisation of male-specific accessory gland cDNAs from D. melanogaster and, moni···.recently, Drosophila simulans. The work presented in this' thesis identified thirty proteins in the accessory gland of D. melanogaster. Fourteen proteins have predicted secretory signals and thus are secreted accessory gland proteins. They included protein-folding and stressresponse proteins, a hormone, a lipase, a serpin, a cysteine-rich protein and three peptidases, a pro-enzyme form of a cathepsin K-like cysteine peptidase, Angiotensin converting enzyme and a y-glutamyl transpeptidase. Biochemical assays of the peptidase levels show the y-glutamyl transpeptidase and Angiotensin converting enzyme are reduced in mated males accessory gland suggesting their prescence in the seminal fluid. The ultrastructure of the accessory gland and secretions were investigated by electron microscopy. The filamentous contents of the secondary cells and lumen were studied by negative staining electron microscopy and cryo-electron microscopy as well as by proteomic methodologies. The major protein component of the filaments was identified as Acp36DE, which is known to be involved in sperm storage thus suggesting that is the role for the filaments.
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Reed, Laura Katie. "The Genetic Relationships of the Sister Species Drosophila Mojavensis and Drosophila Arizonae and the Genetic Basis of Sterility in their Hybrid Males." Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/194437.
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The cactophilic Drosophila mojavensis species group living in the deserts and dry tropical forests of the Southwestern United States and Mexico provides a valuable system for studies in diversification and speciation. My dissertation addresses a variety of evolutionary genetic questions using this system.Rigorous studies of the relationships between host races of D. mojavensis and the relationships among the members of the species group (D. mojavensis, D. arizona, and D. navojoa) are lacking. I used mitochondrial CO1 sequence data to address the phylogenetics and population genetics of this species group (Appendix A). In this study I have found that the sister species D. mojavensis and D. arizonae share no mitochondrial haplotypes and thus show no evidence for recent introgression. I estimate the divergence time between D. mojavensis and D. arizonae to be between 0.66 and 0.99 million years ago. I performed additional population genetic analyses of these species to provide a basis for future hypothesis testing.In Appendix B, I report the first example of substantial intraspecific polymorphism for genetic factors contributing to hybrid male sterility. I show that the occurrence of hybrid male sterility in crosses between Drosophila mojavensis and its sister species, D. arizonae is controlled by factors present at different frequencies in different populations of D. mojavensis. In addition, I show that hybrid male sterility is a complex phenotype; some hybrid males with motile sperm still cannot sire offspring.The large degree of variation between isofemale lines in producing sterile hybrid sons suggests a complex genetic basis to hybrid male sterility warranting quantitative genetic analysis. Since the genes underlying hybrid male sterility in these species are not yet fixed, I am able to perform explicit genetic analysis of this reproductive isolating mechanism. In Appendix C, I present the results of mapping QTL for hybrid male sterility within species. The genetic architecture underlying hybrid male sterility when analyzed directly in the F1 is highly complex. Thus, hybrid male sterility arises as a complex trait in this system and we propose a drift-based model for the evolution of this phenotype.
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El, Sharnouby Sherif Maher. "Methodology for genome-wide epigenetic profiling of the Drosophila male germline." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609941.
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Innocenti, Paolo. "Sexual Conflict and Gene Expression in Drosophila melanogaster." Doctoral thesis, Uppsala universitet, Zooekologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-156567.
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Sexual conflict is broadly defined as a conflict between the evolutionary interests of the two sexes. Depending on the genetic architecture of the traits involved, it can occur at the level of male-female interactions or take the form of selection acting to change the mean of a shared trait against the sign of its genetic correlation. The aim of my thesis was to use genome-wide expression profiles in the model organism Drosophila melanogaster to provide novel insights in the study of sexual conflict. First, we studied the female post-mating response to partition transcriptional changes associated with reproduction from male-induced effects, which are known to be harmful to females. We found substantial changes in expression of metabolic pathways associated with the activation of reproduction, while male-specific effects were dominated by the onset of an immune response. Changes in female response under different mating strategies was studied using experimental evolution: we found that monogamous females suffered decreased fecundity and their gene expression profiles suggested an overall weaker response to mating. To identify sexually antagonistic genes, we used hemiclonal lines and associated their sex-specific fitness with genome-wide transcript abundance. We confirmed the presence of a negative covariance for fitness and identified a group of candidate genes experiencing sexually antagonistic selection. We then focused on mitochondria, which can enable the accumulation of deleterious mutations with sex-specific effects due to their maternal inheritance, and found few effects on nuclear gene expression in females but major effects in males, predominantly in male-specific tissues. Finally, we used published data to compare intraspecific and interspecific genetic variation for a set of transcripts, to test whether speciation occurs along lines of maximum genetic variance. In conclusion, gene expression techniques can generate useful results in the study of sexual conflict, particularly in association with phenotypic data or when integrated with published datasets.
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Pavlou, Hania Jamil. "Intersecting doublesex neurons underlying sexual behaviours in Drosophila melanogaster." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:5e193063-fcea-4652-b8ad-25632b379298.
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In Drosophila, the functionally conserved transcription factor, doublesex (dsx), is pivotal to the specification of sexual identity in both males and females. One of its key dedicated roles involves regulating the development of a sexually dimorphic nervous system (NS) that underlies both male and female reproductive behaviours. Specific inhibition of the function of dsx-expressing neurons in males and females results in a global disruption of these sex-specific behavioural outputs. However, little is known about the functional organisation of this dsx circuit that encodes the potential to display these behaviours. Such investigations require the generation of a novel transgenic tool, capable of separating the function of dsx in the NS from that of the body. To achieve this, I generated a novel split-GAL4 dsxGAL4-DBD hemidriver by ends in homologous recombination. Coupling the novel tool with the pan-neuronal elavVP16-AD hemidriver, revealed spatial restriction of dsxGAL4-DBD/elavVP16-AD expression to dsx neurons only; enabling the realisation of novel patterns of dsx-expression in the peripheral NS. Next, the ability to elicit male-specific behavioural outputs upon activation of all dsx neurons formed the basis of a large behavioural screen aimed at parsing dsx circuitry into functionally distinct clusters. I utilised the novel dsxGAL4-DBD hemidriver to screen a large collection of extant enhancer trap lines (ETVP16-AD), for the elicitation of distinct sub-behaviours of male courtship. Here, I show that the activity of dsx-expressing clusters in: i) the brain (dsx-pC1, -pC2 and -pC3 collectively) regulate the early steps of male courtship (initiation, orientation and wing extension), ii) the pro- and mesothoracic ganglia (dsx-TN1 and -TN2) regulate the middle steps of male courtship (wing extension and possibly courtship song) and iii) the abdominal ganglia (dsx-Abg) regulate the late steps of male courtship (abdominal curling, attempted copulation and copulation). These data establish functional correlations between dsx clusters in distinct neuroanatomical foci and specific sub-behaviours of the courtship repertoire. Furthermore, the novel intersectional tool primed a collaborative study on female post-copulatory behaviours. We identified key sensory neurons in the female reproductive tract involved in initiating post-mating behaviours. Subsequent functional interrogations of dsx circuitry in the central NS revealed a subset of dsx-expressing neurons in the Abg that mediate changes in the female behavioural repertoire after mating. Characterisation of this relatively simple neural circuitry sheds light on the organisation of the fly brain. Ultimately, future studies will define principles of neural circuit operation, which may be similarly conserved in the nervous systems of higher animals.
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White, Alison. "Assessing Territoriality as a Component of Male Sexual Fitness in 'Drosophila serrata'." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24020.
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While the phenotypic effects of sexual selection have been well studied, the consequences for population mean fitness remain unclear. Additionally, there is a need to more fully characterize how various forms of inter- and intrasexual selection combine to affect the evolution of traits under sexual selection. Here, I address these issues as they relate to male territoriality in Drosophila serrata, a model system for the study of female preference for male pheromones. First, I demonstrate that territoriality occurs and is a likely component of male sexual fitness. Results from a phenotypic manipulation indicate that territorial success was also condition-dependent, and that sexual selection against low condition males tended to be stronger given a high opportunity for territory defense. Territorial success depended on body size but not on pheromones. How this and other components of male mating success interact to affect trait evolution and population mean fitness remains an important area for future study.
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Billeter, Jean-Christophe. "Targeting fruitless neurons : neurogenetic dissection of male sexual behaviour in Drosophila melanogaster." Thesis, University of Glasgow, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411778.
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Rylett, Caroline McGinn. "Peptidases of the testes and accessory glands of the male Drosophila melanogaster." Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434584.
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Murtfeldt, Eric Robert. "Consequences of ectopic JAK/STAT pathway activation in the Drosophila male germline." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p1457319.
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Thesis (M.S.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed November 5, 2008). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 51).
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Huttunen, S. (Susanna). "Genetic basis of male courtship song traits in Drosophila virilis." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514269527.
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Abstract
The pattern and the genetic basis of variation in courtship song of D. virilis were studied using three different approaches: a candidate gene, a biometrical and a quantitative trait locus (QTL) method. Nucleotide variation in a candidate song gene, no-on-transientA, was analysed both within the species (D. virilis and D. littoralis) and between the species of the D. virilis group. Nucleotide variation showed no signs of selection and there was no association between the nucleotide or repeat length variation in nonA gene region and the song characters of the D. virilis group species.
Molecular markers (microsatellites) were isolated for D. virilis and their cross-species amplification was tested in all members of the D. virilis group. Intraspecific variation in D. virilis was studied at the phenotypic level in male song characters and at the genetic level in microsatellites. Significant geographic variation was detected in both levels, grouping the strains according to the main continents of the species' distribution range: America, Asia, Europe and Japan. The strains with most extreme song phenotypes were chosen for further analysis. The inheritance of two courtship song characters, the number of pulses in a pulse train (PN) and the length of a pulse train (PTL) was studied by analysing the means and variances of these characters between parental and reciprocal F1, F2 and backcross males. This biometrical analysis showed the genetic basis of these song characters to be polygenic with significant dominance, epistatic and Y-chromosomal effects on both characters. A subset of these data (F2 generation males) were used to conduct a QTL study with the aid of a recombination linkage map constructed for the microsatellites. Composite interval mapping (CIM) revealed significant QTLs, which were shared in both characters. Altogether, significant QTLs, located on the X, 2nd, 3rd and 4th chromosome, were found to affect PN, whereas only QTLs on the 3rd chromsome was found to affect PTL. The effect of the same QTL on the 3rd chromosome on both characters accounted for 31.8% and 49.1% of the mean difference between the parental strains in PN and PTL, respectively. These results suggest the genetic basis for these song characters is caused mainly by autosomal QTLs with a relatively large effect.
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Lee, Soojin 1980. "Lasp is required for anchoring of the male stem cell niche and spermatid individualization in Drosophila." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112532.
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Drosophila Lasp contains a LIM domain, two nebulin repeats, and a SH3 domain, and exhibits high homology with mammalian Lasp family proteins. Vertebrate Lasp localizes to focal adhesions and to the leading edge of migrating cells and binds filamentous actin. To investigate Drosophila Lasp in vivo, we generated a Lasp null mutant, named Laspl, and showed that Laspl is male sterile. We observed two major functions of Lasp during Drosophila spermatogenesis. First, in the stem cell niche, hub cells fail to localize to the apical end of Drosophila testis in Laspl mutant. Hub cell anchoring is dependent on cell adhesion between cells and extracellular matrix (ECM), which is mediated by integrins. Lasp genetically interacts with betaPS integrin showing complete hub cell mislocalization. This indicates that Lasp is involved in an integrin-dependent process. However, hub cell anchoring is not required for fertility or stem cell maintenance. Secondly, we observe that actin cones, a unique actin structure during spermatid individualization, are perturbed in Laspl. Our data for Lasp expression in actin cones and incomplete individualization indicate that Lasp may play a role in tethering actin to the plasma membrane.
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JIN, TUO. "Dietary effects on late-life mortality rates of male and female Drosophila melanogaster." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-176884.
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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.
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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.
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PERRIN-WALDEMER, CLAUDE GILBERT. "Etude des glandes accessoires du male de drosophila melanogaster (meigen) : cytophysiologie et cytochimie." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF2E359.
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Guo, Ruijian. "Genetic and environmental components of sperm function in Drosophila melanogaster." Technische Universität Dresden, 2019. https://tud.qucosa.de/id/qucosa%3A37772.
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Sperm function has been studied in multiple research fields as it is essential to male fertility. In previous studies a variety of sperm traits have been examined as an assessment of sperm function. Among those traits, sperm viability, sperm motility and sperm metabolism are often commonly examined. However, sperm function can be influenced by both environmental and genetic factors. Specifically, nuclear genome has been demonstrated to play a role in sperm function, especially in sperm competitive capacity. There are increasing evidence for effects of mitochondrial genome on sperm function. Mitochondrial genetic variance has been suggested to
affect sperm length and sperm viability in seed beetle and sperm metabolism in rodent. Given the coordinated collaborations between nuclear and mitochondrial genomes in OXPHOS, replication and transcription of mitochondrial genome as well as intergenomic signalling, potential mitonuclear effects on sperm function are expected even though empirical evidence so far remains less. A recent review summarised all the previous work on environmental effects on sperm and found that various factors affects sperm function but largely neglected in ecology and evolution. In the study, we used D. melanogaster as a model to disentangle both genetic and environmental components of sperm function at sperm cell, ejaculate and offspring levels.
We found environmental effects on sperm function in D. melanogaster. Specifically, sperm incubation buffers affect sperm viability in chapter 2 and dietary PUFAs influence sperm volume and metabolism in chapter 4. Nuclear effects were found on sperm viability, sperm quality and male fertility in chapter 3. Mitochondrial genome was found to have an effect on sperm function, i.e. sperm viability and sperm quality differed among mitochondrial haplotypes examined. In addition, sperm function was further modified by the interaction of nuclear and mitochondrial genomes in ageing male. Sperm quality and fertilization success were suggested to be dependent on age-related mitonuclear interaction in chapter 3. Moreover, we examined the mitonuclear coadaptation hypothesis in the function of D. melanogaster sperm. No evidence for mitonuclear coadaptation hypothesis was found for sperm function in D. melanogaster as there were no difference between coadapted and non-coadapted lines in sperm traits examined. Lastly, we found that sperm viability, sperm quality and sperm metabolic rate cannot predict male fertility in D. melanogaster as correlation analysis revealed no relationship between them. Our experiment explored and disentangled the genetic and environmental components of sperm function at multiple levels in D.melanogaster systematically. Our results suggested that both mitochondrial and nuclear genome as well as the interaction between them play a role in sperm function in D. melanogaster. In addition to genetic components, our findings revealed environmental components of Drosophila sperm and suggested that it was phenotypic plastic.
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French, Rachael Louise. "Molecular and genetic characterization of the function of tramtrack in dorsal appendage morphogenesis in Drosophila melanogaster /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/10277.
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Boone, James. "The roles of reproductive proteins in determining male and female fitness in Drosophila melanogaster." Thesis, University of East Anglia, 2011. https://ueaeprints.uea.ac.uk/36325/.
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In this thesis I use Drosophila melanogaster as a model organism to study the roles of reproductive proteins in determining male and female fitness. Many of these proteins are likely involved in mediating sexual conflict between the sexes, therefore I focus on how males and females interact at the molecular level, in order to gain insight into the mechanisms underlying sexually antagonistic coevolution. I provide the context for the work (Chapter 1) and describe the general methods and stocks used throughout (Chapter 2). I show that the sex peptide receptor (SPR) found in females, dramatically changes the fitness benefits to males after early rematings (Chapter 3), I also describe my investigation into the structure of the mating plug formed within females mated to males lacking the mating plug protein, PEBII (Chapter 4). I then test two candidate genes, Acp26Aa and Spn2, for roles in sperm competition and compare the results obtained from functional tests and correlative studies (Chapter 5). Next, I focus on the requirement of sex peptide (SP) for SPR and vice versa for inducing feeding responses in mated females and early changes in post mating egg laying and receptivity (Chapter 6). Carrying on from this, I investigate the role of SP and its related protein, Dup99B, in eliciting post mating responses in females (Chapter 7), Finally, I summarise the findings from my thesis and discuss ideas for future work to increase our understanding of the consequences of sexual conflict and sexually antagonistic coevolution in Drosophila melanogaster (Chapter 8). My research shows that reproductive proteins play important roles in determining male and female fitness and provides further data supporting how sperm competition and molecular interactions between the sexes can generate and maintain genetic variation for sexual traits.
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Cooperman, Alison Fay. "Male secondary sexual traits and mating behavior in the species drosophila bipectinataduda (Diptera: Drosophilidae)." Cincinnati, Ohio : University of Cincinnati, 2006. http://rave.ohiolink.edu/etdc//view?acc_num=ucin1155750119.
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Thesis (M.S.)--University of Cincinnati, 2006.Advisor: Dr. Michal Polak. Title from electronic thesis title page (viewed Dec. 21, 2009). Includes abstract. Keywords: D. bipectinata; sexual selection; good genes. Includes bibliographical references.
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Ashley, Elizabeth L. "Whole-genome analysis of the transcriptional network underlying male sexual behaviour in Drosophila melanogaster." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:30c20b2e-95c1-4dbe-ae8a-aa2cb869b4a2.
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The robust behavioural courtship ritual displayed by Drosophila melanogaster males is governed by their underlying nervous system (NS). Two key genes of the Sex Determination Hierarchy, fruitless (fru) and doublesex (dsx), determine most neuronal substrates for sexual behaviour. In this study we aim to better understand the role fru plays in determining these neural substrates, as a means of better understanding the relationships between brain, behaviour and genes, and thus how the development of neuronal networks shape innate and species-specific behaviours. Fru has two major functions: control of male sexual behaviour, and viability in both sexes. Alternative splicing of fru produces transcription factors driven by four promoters: P1 transcripts are sex-specifically spliced (only viable in the male), and P2-4 transcripts are crucial to both sexes survival. The resulting proteins contain a BTB protein-protein interaction domain at the N-terminus, and one of four C-terminal zinc-finger (ZnF) DNA binding domains. Male-specific proteins (FruM) contain an additional 101 amino acid N-terminal domain, and one of three alternative C2H2 ZnF domains (FruMA, FruMB, FruMC). These male-specific isoforms are expressed in the central nervous system (CNS) beginning in the late stage larvae (L3), peaking during pupation and on into adulthood. Little is known, however, about the roles of the individual isoforms, and no clear transcriptional targets have been identified. The central aims of this thesis are to document the wild-type expression patterns of Fru isoforms throughout development in the CNS, create and characterise isoform-specific mutants, and to identify and evaluate putative transcriptional targets of Fru. Combining these findings will lead to a better understanding of the underlying molecular functions of individual FruM isoforms, as a means to understanding their roles in sexual behaviour. Expression analysis of FruM isoforms throughout development in the NS is described. To further characterise the role of individual FruM isoforms, isoform-specific mutants in fruA and fruB exons were generated using site-specific homologous recombination (HR). These novel mutants were validated by PCR and Fru isoform-specific antibody stainings. Mutants were analysed in fruM- and fru-null genetic backgrounds, to distinguish the roles of sex-specific vs. common isoforms. These analyses included: fertility, viability and morphology. FruA was found to have a role in wing extension with possible repercussions for song production. FruB was found to be developmentally lethal, in addition to having defects in male courtship behaviour. To understand the role of fru in the NS, downstream transcriptional targets of FruM isoforms were identified. DNA adenine methyltransferase identification (DamID) was used to identify putative transcription targets of FruM isoforms. The Dam protein methylates DNA in Drosophila in a sequence-specific manner allowing targets of Fru to be isolated. Candidate genes were identified using computational analysis (including gene ontology, peak analysis and motif analysis) along with a biologically significant connection with fru. The relationship between fru and six candidate genes were characterised using RNAi. The results of these studies advance our knowledge of how FruM isoforms influence the development and physiology of the NS underlying male sexual behaviour in Drosophila.
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Suvanto, L. (Leena). "Mate choice and genetic variation in male courtship song in Drosophila montana." Doctoral thesis, University of Oulu, 1999. http://urn.fi/urn:isbn:9514251911.
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Abstract
This thesis deals with factors affecting mate choice as well
as with genetic variation in male courtship song in Drosophila
montana. Males, which produced song with a high carrier
frequency, were found to court females, and also to succeed in
their courtship more often than the males producing low frequency
song. Male mating success correlated with the carrier frequency
of his song recorded after, but not before, an "artificial
winter", which suggests that a sexually selected male
trait is sensitive to environmental factors. A high carrier frequency
of male courtship song correlated positively with the survival
rate of the male's progeny from egg to adulthood (indirect
benefit for the female), but not with the fecundity of his mating
partner (no direct benefit for the female).
The heritabilities and the amount of additive and residual
variation in male courtship song characters were measured in two
populations using father-son regression and sib analysis. The songs
of the males from one of these populations were analysed for a
second time after the cold treatment. Most heritability values
were insignificant, largely due to high residual variation. During
the cold treatment, the additive variation increased and the residual
variation decreased in almost all song traits. Increased variation
in sexually selected traits may help the females to exercise selection between
the males during the mating season of the flies in the wild in
spring. This, and the fact that male song gives the female information
about the male's condition/genetic quality suggests
that in this species the evolution of female preferences for male
song characters could have evolved through condition-dependent
viability selection as postulated by "good genes" models.
Variation and inbreeding depression/heterosis were
studied in traits associated with fly reproduction using inbred
D. montana strains. Songs, hydrocarbons and some behavioural traits
of the flies varied significantly between strains. The strain of
both sexes affected female egg-laying, and the female strain, also,
the survival rate of the flies' progeny, in different
intra- and interspecific combinations. Heterosis was found in the
mating propensity of the flies and in the carrier frequency of
the male song. Diallel analysis revealed unidirectional dominance
towards higher carrier frequency. This direction is the same as
the direction of sexual selection exercised by the females of this
species suggesting that sexual selection could be a driving force
in evolution of this song trait.
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Fitzpatrick, Kathleen Anne. "The effect of chromatin structure on P element-induced male recombination in Drosophila melanogaster." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24664.
Full textAbstract:
Dysgenic male recombination (MR) induced by the P strains T-007 and OKI rarely, if ever, occurs in the heterochromatin of chromosome two. One possible explanation is that the lack of heterochromatic exchange is due to the highly condensed chromatin in this region. Butyrate (a suspected modifier of chromatin structure) induced significant levels of heterochromatic MR in dysgenic hybrids derived from crosses involving two different P strains. This finding is consistent with the hypothesis that chromatin structure can influence the insertion and excision of P elements and hence MR. Analogous experiments were performed using third chromosome suppressor of variegation (Su(var)) mutations. Neither suppressor mutation induced any heterochromatic MR, suggesting that the mode of action of these Su(var) genes is different from, and more specific than, that of butyrate. One of the mutations (325) which is thought to influence meiotic recombination frequencies, causes some alterations in euchromatic MR in crosses involving the OKI strain. The other mutation, 318, affects neither meiotic nor dysgenic recombination. Su(var) 325 is the first known "factor" to influence meiotic and dysgenic recombination similarly.Science, Faculty of
Zoology, Department of
Graduate
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Saarikettu-Känsälä, M. (Mari). "Coevolution of male signals and female preferences in Drosophila montana and D. virilis." Doctoral thesis, Oulun yliopisto, 2011. http://urn.fi/urn:isbn:9789514296659.
Full textAbstract:
Abstract Divergence of behavioral traits (e.g. courtship rituals, habitat choice) has had a major impact on species formation and isolation. Species-specific courtship rituals preventing species hybridization may arise as a by-product of natural selection during spatial isolation or through direct action of natural selection to prevent species hybridization after a secondary contact. Coordination leading to the assumption of coevolution of signals and preferences is a prerequisite for effective courtship signaling between a male and a female of the same species. We found a reasonable amount of variation in the mate traits within the Drosophila montana and D. virilis species, but our findings did not reveal evidence of the coevolution between the male courtship signals and female preference for these signals. Variation also did not cause isolation within species. The form of female preference for carrier frequency of male song was found to be stabilizing even in changing environments, when female preference for the carrier frequency and pulse length of the male song was measured at ambient temperature. D. montana females always preferred males with high frequency songs, which probably advertises the male condition. The frequency of male song decreased due to male aging, although males with larger body size were able to maintain frequencies better. Ageing also had a deterioration effect on male reproductive success. The importance of male courtship song was not only highlighted in mate choice, but also in species-recognition. We were able to persuade D. montana females to copulate with alien D. lummei species by playing them simulated song resembling the song of conspecific males. Simulated courtship songs were demonstrated to be a practical tool in studies of preference between sexually isolated Drosophila speciesTiivistelmä Kosintapiirteiden (esim. kosintarituaalit, habitaatin valinta) vaihtelevuudella on ollut suuri vaikutus lajien muodostumisessa ja eriytymisessä. Lajien välisiä risteytymisiä estäviä lajispesifisiä kosintarituaaleja voi syntyä luonnonvalinnan sivutuotteena spatiaalisen eristäytymisen aikana tai luonnonvalinnan suoralla vaikutuksella estämään lajiristeymät lajien uudelleen kohdatessa. Tehokkaan koiraan ja naaraan välisen kosintaviestinnän edellytyksenä on koordinointi, minkä vuoksi on oletettavaa, että signaalien ja vasteiden välillä on yhteisevoluutiota. Löysimme kohtuullisen määrän vaihtelevuutta kosintapiirteissä Drosophila montana – ja D. virilis – lajeilla, mutta emme löytäneet todisteita koiraan kosintasignaalien ja naaraan näihin signaaleihin kohdistamien vasteiden välisestä yhteisevoluutiosta. Vaihtelu ei myöskään aiheuttanut isolaatiota lajien välille. Naaraan koiraan kosintalaulun kantofrekvenssiin osoittaman vasteen funktion muodon havaittiin olevan tasapainottava jopa vaihtelevissa ympäristöissä, kun naaraan kantotaajuuteen osoittamaa vastetta mitattiin eri lämpötiloissa. D. montana naaraat suosivat koiraita, joilla oli korkeataajuinen kosintalaulu. Laulun korkea taajuus kertoo luultavasti naaraalle koiraan fyysisestä kunnosta. Koiraan laulun frekvenssin havaittiin laskevan koiraan ikääntyessä, mutta isommat koiraat pystyivät paremmin säilyttämään korkean taajuuden laulussaan. Ikääntyminen heikensi myös koiraan lisääntymismenestystä. Koiraan kosintalaulun tärkeys ei korostunut pelkästään parinvalinnassa, vaan myös lajintunnistuksessa. Pystyimme suostuttelemaan D. montana –naaraat parittelemaan vieraan D. lummei –lajin kanssa käyttämällä simuloituja kosintalauluja, jotka osoittautuivat käytännöllisiksi välineiksi tutkittaessa naaraan vasteita seksuaalisesti eriytyneillä Drosophila-lajeilla
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Cheng, Wei. "From Neurodegeneration to Infertility and Back - Exploring Functions of Two Genes: ARMC4 and TARDBP: A Dissertation." eScholarship@UMMS, 2014. http://escholarship.umassmed.edu/gsbs_diss/695.
Full textAbstract:
Amyotrophic Lateral Sclerosis (ALS) is an adult-onset progressive neurodegenerative disease that causes degeneration in both upper and lower motor neurons. ALS progresses relentlessly after the onset of the disease, with most patients die within 3-5 years of diagnosis, largely due to respiratory failure. Since SOD1 became the first gene whose mutations were associated with ALS in 1993, more than 17 ALS causative genes have been identified. Among them, TAR DNA-binding protein (TARDBP) lies in the central of ALS pathology mechanism study, because TDP43 proteinopathy is observed not only in familial ALS cases carrying TARDBP mutations, but also in most of the sporadic ALS cases, which account for 90% of the whole ALS population. Several TDP43 overexpression mouse models have been successfully generated to study the gain-of-toxicity mechanism of TDP43 in ALS development, while the investigation of loss-of-function mechanism which could also contribute to ALS still awaits a proper mouse model. The major difficulty in generating TARDBP knock out mouse model lies in the fact that TARDBP is a development essential gene and complete depletion of TDP43 function causes embryonic lethality.
In chapter I, I reviewed the recent advances in ALS study. Emphasis was given to ALS mouse models, especially TARDBP ALS mouse model.
In Chapter II, I made a Tet-responsive construct that contains mCherry, a fluorescent protein, as an indicator for the expression of the artificial miRNA (amiTDP) residing in the 3’UTR of mCherry and targeting TARDBP. The construct was tested in NSC34 cells and TRE-mCherry-amiTDP43 transgenic mouse was generated with this construct. Crossing TRE-mCherry-amiTDP43 mouse with mPrp-tTA mouse, mCherry expression was successfully induced in mouse forebrain and cerebellum, but not in other tissues including spinal cord. By quantitative real-time PCR, amiTDP43 expression was confirmed to be coupled with mCherry expression. Fluorescent immunostaining revealed that mCherry was expressed in neurons, but not in astrocytes or microglia cells, and that in mCherry positive cells, TDP43 was significantly knocked down. Results from Nissl staining and GFAP immunostaining suggested that decrease of TDP43 in forebrain neuron only was not sufficient to cause neurodegeneration and neuron loss.
In chapter III, I investigated the function of Armadillo Containing Protein 4 (ARMC4), which was originally considered ALS causative gene. Our study of the function of CG5155, the possible homolog of ARMC4 in Drosophila, indicated that CG5155 is a male fertility gene that is involved in spermatogenesis. Therefore, we have named this gene Gudu. The transcript of Gudu is highly enriched in adult testes. Knockdown of Gudu by a ubiquitous driver leads to defects in the formation of the individualization complex that is required for spermatid maturation, thereby impairing spermatogenesis. Furthermore, testis-specific knockdown of Gudu by crossing the RNAi lines with Bam-Gal4 driver is sufficient to cause the infertility and defective spermatogenesis. Since Gudu is highly homologous to vertebrate ARMC4, also an Armadillo-repeat-containing protein enriched in testes, our results suggest that Gudu and ARMC4 is a subfamily of Armadillo-repeat containing proteins with an evolutionarily conserved function in spermatogenesis.
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Zhou, Lili. "The role of Lasp in the «Drosophila» male stem cell niche and in muscle development." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95064.
Full textAbstract:
Drosophila Lasp is the only member of the nebulin family in Drosophila. Lasp has an amino-terminal LIM domain, two actin-binding nebulin repeats and a carboxyl-terminal SH3 domain and exhibits very high homology to human Lasp. To assess Lasp function in vivo, we generated a null mutant in Drosophila Lasp, named Lasp1. Lasp1 mutants are homozygous viable, but male sterile. Lasp localizes to cyst cells, early germ cells, hub cells and actin cones. In Lasp1 mutants, the stem cell niche is no longer anchored to the apical tip of the testis, and actin cone migration is perturbed resulting in improper spermatid individualization. Lasp colocalizes with βPS integrin and genetically interact with βPS integrin resulting in complete hub cell mislocalization, which indicates that Lasp modulates integrin adhesion in this context. Lasp1 mutant larvae and flies also have impaired crawling, climbing and flying ability. Lasp localizes to Z lines of third instar larval body wall muscles. In Lasp1 mutant indirect flight muscle, thin filament and sarcomere length is reduced while sarcomere ultrastructure is not significantly affected. The same applies to larval body wall muscles, where we observe a misregulation of sarcomere length in both absence and overexpression of Lasp. This phenotype is very similar to nebulin mutant knock-out mice indicating that Lasp plays a role in regulating thin filament lengths, but with only two nebulin repeats.Chez la drosophile, Lasp est la seule protéine représentante de la famille des Nébuline. Lasp contient un domaine LIM, deux répétitions de type Nébuline et un domaine SH3, et présente une forte homologie avec la famille Lasp des mammifères. Afin identifier le rôle de Lasp, nous avons généré une mutation nulle, nommée Lasp1. Les mutants Lasp1 sont homozygotes viables, mais les mâles stériles. Lasp se localise dans cellules kyste, dans les cellules germinales, les cellules hub et au niveau des cônes d'actine. Chez les mutants Lasp1, les cellules souches ne sont plus ancré à l'extrémité apicale du testicule, et la migration des cônes d'actine est perturbée, conduisant à une individualisation irrégulière des spermatides. Lasp est colocalisée avec l'intégrine βPS et interagit génétiquement avec l'intégrine βPS, amenant une délocalization des cellules hub, indiquant que Lasp module adhésion intégrine dans ce contexte. Les larves mutantes pour Lasp se déplacent avec difficulté et les adultes ont avec une capacité d'escalade et de vols réduite. Lasp se localise aux lignes Z dans les muscles des larves du troisième stade. Chez les adultes Lasp1, les muscles des ailes présentent une longueur réduite des filaments minces ainsi que des sarcomères, alors que l'ultrastructure du sarcomère ne semble pas être significativement affectée. Les muscles larvaires présentent le phenotype. De plus, on observe un dérèglement de la longueur du sarcomère en surexprimant Lasp dans un contexte sauvage. Ce phénotype est très similaire à celui des souris mutantes pour la nébuline, indiquant que Lasp joue un rôle dans la régulation de la longueur du filament mince, mais avec seulement deux répétitions nébuline.
27
Corrigan, Laura. "Regulation and reproductive functions of membrane-bound vesicles secreted by the Drosophila male accessory gland." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:673d46a5-ba88-42d2-9361-51f04d61e01b.
Full textAbstract:
Membrane-bound vesicle secretion provides a novel intercellular communication mechanism, whose roles and regulation remain poorly characterised, particularly in vivo. I have identified two classes of lipid-containing, vesicle-like structures secreted into seminal fluid by epithelial cells of the Drosophila male accessory gland (AG). Exosomes, one class of membrane-bound vesicle formed inside late endosomal multivesicular bodies, are specifically secreted by secondary cells (SCs). The unusual cell biology of SCs allowed me to develop a powerful new high resolution in vivo system to characterise the mechanisms underlying intracellular membrane trafficking events underlying exosome biogenesis using real-time live imaging. I characterise how specific ESCRTs (endosomal sorting complexes required for transport) control SC exosome biogenesis, and identify a novel role for BMP signalling in regulating endolysosomal trafficking events necessary for exosome secretion. I also identify roles for epidermal growth factor receptor (EGFR) and phosphatidylinositide 3-kinase (PI3K) signalling in exosome biogenesis. Importantly, SC exosomes are transferred to females during mating. Here, they fuse with sperm, mirroring in vitro interactions between human prostate exosomes and sperm, and interact with the female reproductive tract epithelium. Blocking SC exosome production specifically suppresses post-mating effects on female receptivity to remating, demonstrating that exosomes have an important reproductive signalling function in vivo, directly or indirectly reprogramming female cells. Finally, I show that main cells, the major epithelial AG cell type, shed lipid-containing microvesicle-like structures from their apical surface. Remarkably, these vesicles carry the seminal peptide, sex peptide, into females during mating and also contribute to the anterior mating plug. In summary, my data reveal previously unsuspected roles for exosomes and microvesicles in Drosophila reproduction that may be evolutionarily conserved. Since these vesicles mediate physiological processes previously thought to involve soluble peptides, my work suggests that current models explaining male reprogramming of female behaviours in flies and higher organisms need substantial revision.
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ANTONIOU, ANTONAKIS. "Influences genetiques et epigenetiques sur le comportement sexuel du male de drosophila melanogaster : aspects ethologiques, pharmacologiques, evolutifs." Toulouse 3, 1986. http://www.theses.fr/1986TOU30027.
Full textAbstract:
Comparaison de 3 souches, americaine, africaine et europeenne. Confirmation de l'origine africaine de l'espece. Le mutant dunce**(2) presente une diminution de la vigueur sexuelle et des capacites d'apprentissage. Le comportement sexuel est modulable par les conditions de developpement du male pendant la vie imaginale (isolement, obscurite, reduction de l'espace, inhibiteur de synthese de la serotonine dans le milieu nutritif). Mise en evidence d'un phenomene d'inhibition sexuelle en relation avec l'experience individuelle du male
29
Cooperman, Alison Fay. "Male Secondary Sexual Traits And Mating Behavior in the Species Drosophila Bipectinata Duda (Diptera: Drosophilidae)." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1155750119.
Full text
30
Sztepanacz, Jacqueline L. P. "The Genetic Limits to Trait Evolution for a Suite of Sexually Selected Male Cuticular Hydrocarbons in Drosophila Serrata." Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20385.
Full textAbstract:
Directional selection is prevalent in nature yet phenotypes tend to remain relatively constant, suggesting a limit to trait evolution. The genetic basis of evolutionary limits in unmanipulated populations, however, is generally not known. Given widespread pleiotropy, opposing selection on a focal trait may arise from the effects of the underlying alleles on other fitness components, generating net stabilizing selection on trait genetic variance and thus limiting evolution. Here, I look for the signature of stabilizing selection for a suite of cuticular hydrocarbons (CHCs) in Drosophila serrata. Despite strong directional sexual selection on CHCs, genetic variance differed between high and low fitness individuals and was greater among the low fitness males for seven of eight CHCs. Univariate tests of a difference in genetic variance were non-significant but have low power. My results implicate stabilizing selection, arising through pleiotropy, in generating a genetic limit to the evolution of CHCs in this species.
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Brule, Veronique. "The role of RBF1 in animal survival and in male germline stem cell differentiation during Drosophila melanogaster development." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119514.
Full textAbstract:
Retinoblastoma (RB) is a tumour-suppressing protein involved in many cellular functions including: cell cycle regulation, cellular differentiation and cell death. In the past, its function has been intrinsically linked to its role in the cell cycle, wherein it acts as a key regulator of the G1 to S-phase transition checkpoint. However, evidence has emerged in support of cell cycle-independent roles for RB. In particular, it has been demonstrated that RB plays an important role in promoting normal animal development and survival to adulthood, a function that is conserved between mammals and metazoans. This role has been extensively studied using RBF1, the Drosophila melanogaster homolog of mammalian RB. An outstanding question in this field is whether or not the mutation of RB results in tissue-specific biological outcomes that ultimately affect adult viability. The results of this research thesis suggest that the mutation RBF1 can lead to tissue-specific developmental defects; however, the defects observed did not affect the ability of animals in surviving to adulthood. For example, a male germline-specific phenotype was observed when RBF1 expression was absent from germ cells. Adult male flies in which RBF1 expression was absent from the germline were sterile. Upon closer inspection, changes in germ cell number and patterning in the testes were observed. As well, an increase in cyclin E expression in RBF1-null mutants suggested that germ cells were being arrested at an early stage of spermatogenesis. A role for RBF1 in the fly germline has not been previously investigated. Therefore, this research project has identified a novel function of RBF1 with respect to germline regulation. Additionally, this research thesis also aimed to investigate whether RB interacted with a subset of known RB-associating factors in a tissue-specific manner. While this question was not completely addressed by the research presented herein, phosphorylation of Serine 728 on RBF1 was detected in vivo. This site was previously investigated in vitro and was suggested to be a putative phosphorylation target by cyclin/Cdk complexes. Therefore, the data of this research thesis have demonstrated the potential for this site to be phosphorylated in vivo. Further experimentation is required in order to verify the authenticity of this site as an endogenous target of phosphorylation. Overall, the data presented in this research thesis provide new insight into the various roles of RBF1 and the manner in which it is regulated.Le rétinoblastome (RB) est une protéine classifiée comme suppresseur de tumeur. Elle joue plusieurs rôles importants dans la cellule, incluant: la régulation du cycle cellulaire, la différentiation cellulaire et l'apoptose. Dès sa découverte, le rétinoblastome a été caractérisé par son rôle primaire en règlant le cycle cellulaire dans lequel RB fonctionne comme régulateur de la transition entre la phase G1 et la phase S. Depuis ce temps, d'autres rôles pour RB indépendents de son fonctionnement dans le cycle cellulaire ont été identifiés. Notamment, il a été démontré que RB joue un rôle important dans la promotion de processus de dévelopement normal dans l'animal et la survie jusqu'à l'âge d'adulte. La plupart des recherches concentrant sur ce rôle ont été faites en utilisant la Drosophile, une espèce modèle qui convient à la manipulation génétique et en laquelle l'homologue de RB se nomme RBF1.Il reste plusieurs questions à rechercher à propos du rôle de RBF1 concernant la survie de l'animal jusqu'à l'âge d'adulte. Cette thèse essaie de répondre à la question suivante; est-ce que les effets biologiques résultant de mutater RBF1 sont spécifiques à des tissus particuliers, et est-ce qu'ils ont un effet sur l'abilité de la Drosophila de survivre jusqu'au stage d'adulte? Les résultats de cette thèse indiquent qu'en mutant RBF1, il est possible de produire des effets biologiques unique dans des tissus spécifiques. Quand même, aucun de ces effets ont affecté la survie de l'animal. Par example, il a été démontré que RBF1 joue un rôle unique dans le tissu gonade des mâles. Dans des Drosophiles qui n'expriment pas RBF1 dans les cellules de la lignée germinale, les adultes mâles étaient stériles. En examinant les testicules, le phénotype des cellules de la lignée germinale était différent en comparaison au phenotype sauvage. Aussi, le nombre de cellules da la lignée germinale qui expriment la cycline E avait augmenté. Précédemment, il n'y avait pas d'études qui ont recherché un rôle pour RBF1 dans la lignée germinale des Drosphiles mâles; donc, les résultats de cette thèse ont démontré un rôle unique pour RBF1 en régularisant la spermatogenèse dans les Drosophiles.En plus, cette thèse essaie de répondre à une autre question liée à celle ci-haut: est-ce que RB s'associe avec des macromolécules particulières (dont il est déjà connue à faire des associations), mais d'une manière unique à chaque tissu de la Drosophile? Les données de cette thèse ne donnent pas une réponse complète à cette question, mais elles ont identifié in vivo un site de phosphorylation (Sérine 728) sur RBF1. Ce site a déjà été recherché et a été suggéré in vitro d'être une cible de phosphorylation par les complexes Cdk-cyclines. Alors, les données présentées ci-haut démontrent que Sérine 728 peut être phosphorylé in vivo aussi. Plus de recherche est requis pour vérifier si ce site est un cible authentique de phosphorylation endogène in vivo. En conclusion, les données de cette thèse démontrent de nouvelles façons de régler le fonctionnement de RBF1, et elles présentent des informations nouvelles à propos des rôles variés de RBF1 dans la Drosophile.
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Cheng, Becky. "The Role of the Dosage Compensation Complex as a Pathway for Spiroplasma to Induce Male Lethality in Drosophila melanogaster." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/cmc_theses/1540.
Full textAbstract:
Drosophila melanogaster and many other insects harbor intracellular bacterial symbionts that are transmitted vertically from infected host mothers to their offspring. Many of these bacteria alter host reproductive developmental processes in order to increase their transmission success. For example, Spiroplasma, a spirochete that naturally infects D. melanogaster, selectively kills males during mid-embryogenesis while sparing females. Previous studies suggested that Spiroplasma interacts genetically with the male-specific dosage compensation pathway, which causes ~2-fold up-regulation of most genes located on the male’s single X chromosome so that their expression matches the levels found in females who have two Xs. To further test this idea, I used confocal microscopy to visualize dosage compensation complex (DCC) localization and activity in infected as well as uninfected embryos. In the presence of Spiroplasma, the DCC became abnormally mis-localized across the nucleus. This pattern was accompanied by abnormal acetylation of histone H4K16, a mark induced by DCC activity and needed for proper X chromatin remodeling. My results imply that Spiroplasma directly targets the DCC by misdirecting it to uncompensated regions of the genome, an effect that leads to abnormal gene mis-regulation and consequent lethality (work from other members in our group). To further investigate this interaction, we transgenically expressed low levels of MSL-2 in both Spiroplasma infected and uninfected embryos in order to cause ectopic formation of the DCC in the female sex. I found that when infected, female embryos expressing the DCC showed significantly reduced viability in comparison to uninfected transgenic females. This result supports the notion that Spiroplasma uses the DCC in a dominant gain-of-function manner to kill embryos.
33
Godfrey, Corey. "Characterizing Sexual Selection in a Wild Population of Protopiophila litigata (Diptera: Piophilidae) and Analyzing the Combined Effects of Cuticular Hydrocarbons and Wing Interference Patterns on Male Mating Success in Drosophila serrata." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35743.
Full textAbstract:
One of the major research challenges is the ability to test selective forces in a wild population. A recent discovery of a new dipteran species, Protopiophila litigata, can enable researches to test selection in the wild. Most research has focused on mating behaviour, male mating success and senescence. In this study a small sample of wild mating and non-mating flies were collected, cuticular hydrocarbons were extracted and morphometric traits were obtained to assess the strength of sexual selection. There was significant linear sexual selection on cuticular hydrocarbons and, mid tibia length, hind tibia length and wing length. Overall, further establishes P. litigata as a model species for studying selection in the wild.
Earlier studies have demonstrated strong sexual selection on male cuticular hydrocarbons in Drosophila serrata. Recently wing interference patterns have been documented to be under sexual selection in Drosophila melanogaster. A sample of cuticular hydrocarbons and wing interference pattern values were analyzed to understand the combined effects on male mating success. Cuticular hydrocarbons were under sexual selection, however wing interference patterns were not. Overall, this study confirms selection on cuticular hydrocarbons, but highlights the difficulty in accurately capturing and measuring wing interference patterns.
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Paulino, Rafael Marques [UNESP]. "Caracterização molecular e bioquímica de uma esterase macho-específica em Zaprionus indianus." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/92500.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Zaprionus indianus (Diptera:Drosophilidae) é uma espécie provavelmente de origem africana e que rapidamente se dispersou por parte do continente sul-americano. Hoje, indivíduos dessa espécie são encontrados numa amplitude latitudinal de 35°, do Uruguai a Belém (Brasil). Em Z. indianus e nos demais insetos, as esterases constituem um grupo multifuncional e heterogêneo de enzimas que participam da hidrólise de ésteres, além de estarem relacionadas a diversos processos metabólicos. Neste estudo, foram realizadas análises de esterases de Z. indianus e Drosophila melanogaster, em géis de poliacrilamida (PAGE) a 10% de concentração, em indivíduos dos dois sexos e em diferentes fases do desenvolvimento. Os resultados indicaram que algumas carboxilesterases (respectivamente EST-2 e EST-5 de Z. indianus e EST-6 D. melanogaster) apresentam atividade acentuada em machos. Estas enzimas mostraram similaridades nas duas espécies, tais como o mesmo padrão de inibição, expressão principalmente no estágio adulto e aumento da atividade enzimática com o aumento da idade dos indivíduos. As similaridades bioquímicas entre as enzimas dos dois drosofilídeos sugerem ortologia entre seus genes codificadores. Foram então realizadas reações de PCR, utilizando oligonucleotídeos iniciadores desenhados com base na seqüência do gene Est-6 de D. melanogaster e o DNA genômico de Z. indianus. O fragmento amplificado foi seqüenciado, com composição GC de 48,5% e similaridade de 73% com a seqüência do gene de Est-6 de D. melanogaster. A análise da razão das substituições sinônimas e não sinônimas sugere uma proteína sob ação de seleção normalizadora, onde as trocas sinônimas são em sua maioria neutras e as não sinônimas, na maioria das vezes deletérias, foram eliminadas pela seleção natural. A modelagem...
Zaprionus indianus has expanded its geographical distribution since its recent invasion of the South American continent. The first record data of only eight years, and the origin is probably the South Africa. Nowadays, this species can be found in a latitudinal range of 35º, from Uruguay to Belem (Brazil). Esterases comprise a multi-functional and heterogeneous group of enzymes that participated in ester hydrolysis. In insects, they are related to several metabolic processes, including the reproductive function. Esterase patterns in Z. indianus and Drosophila melanogaster were characterized in polyacrylamide gels (PAGE). Two - esterases from Z. indianus, EST-2 and EST-5, showed similarity preference for substrate - naftil acetate and patterns of inhibition as compared to the EST-6 of D. melanogaster, suggesting a possible role in reproductive biology for both enzymes. Biochemical characterization of these esterases and its differential expression in males, suggest orthology among their genes. In this work, the genomic DNA from Z. indianus was submitted to PCR experiments using 3 sets of D. melanogaster Est-6 sequence primers. The PCR products were directly sequenced; its GC content was 48.5% and presented a 73% similarity compared to Est-6 D. melanogaster sequence. Analysis of sequence data, by estimates of nonsynonymous/synonymous rate ratios, showed that the majority of sites evolves under strong or moderate negative selection (81%) and a minority of sites (19%). is under significant positive selection. Molecular modeling indicates that the fundamental structural features important for catalysis are conserved in the esterase of Z. indianus and human bilesalt activated lipase (BAL), which was used as structural model. Structural and sequence comparisons suggest the evolutionary relationship between ...(Complete abstract click electronic access below)
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Grieshop, Karl H. "The adaptive function of male genital spines in the fruit fly Drosophila ananassae [Doleschall] (Diptera: Drosophilidae) revealed by micron-scale laser surgery." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342716250.
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Chakravorty, Samya. "Role of the Drosophila Melanogaster Indirect Flight Muscles in Flight and Male Courtship Song: Studies on Flightin and Mydson Light Chain - 2." ScholarWorks @ UVM, 2013. http://scholarworks.uvm.edu/graddis/1.
Full textAbstract:
Complex behaviors using wings have facilitated the insect evolutionary success and diversification. The Drosophila indirect flight muscles (IFM) have evolved a highly ordered myofilament lattice structure and uses oscillatory contractions by pronounced stretch activation mechanism to drive the wings for high powered flight subject to natural selection. Moreover, the IFM is also utilized during small amplitude wing vibrations for species-specific male courtship song (sine and pulse), an important Drosophila mating behavior subject to sexual selection. Unlike flight, the contractile mechanism and contribution of any muscle gene in courtship song is not known. To gain insight into how separate selection regimes are manifested at the molecular level, we investigated the effect on flight and mating behaviors of mutations in two contractile proteins essential for IFM functions: an IFM-specific protein, flightin (FLN), known to be essential for structural and mechanical integrity of the IFM, and a ubiquitous muscle protein, myosin regulatory light chain (MLC2), known to enhance IFM stretch activation.
Comparison of FLN sequences across Drosophila spp., reveal a dual nature with the N-terminal region (63 aa) evolving faster (dN/dS=0.4) than the rest of the protein (dN/dS=0.08). A deletion of the N-terminal region (fln�N62) resulted in reduced IFM fiber stiffness, oscillatory work and power output leading to a decreased flight ability (flight score: 2.8±0.1 vs 4.2±0.4 for fln+ rescued control) despite a normal wing beat frequency. Interestingly, the FLN N-terminal deletion reduced myofilament lattice spacing and order suggesting that this region is required to improve IFM lattice for enhancing power output and flight performance. Moreover, fln�N62 males sing the pulse song abnormally with a longer interpulse interval (IPI, 56±2.5 vs 37±0.7 ms for fln+) and a reduced pulse duty cycle (PDC, 2.6±0.2 vs 7.3±0.2 % for fln+) resulting in a 92% reduction in their courtship success. This suggested that FLN N-terminal region fine-tunes sexually selected song parameters in D. melanogaster, possibly explaining its hypervariability under positive selection. That FLN N-terminal region is not essential but required to optimize IFM functions of both flight and song, indicate that FLN could be an evolutionary innovation for IFM-driven behaviors, possibly through its role in lattice improvement.
Mutations of the highly conserved MLC2 [N-terminal 46 aa deletion (Ext), disruption of myosin light chain kinase phosphorylations (Phos), and the two mutations put together (Dual)] are known to impair or abolish flight through severe reductions in acto-myosin contractile kinetics and magnitude of the stretch activation response. Unlike FLN, these MLC2 mutations do not show a pleitropic effect on flight and song. Flight abolished Phos and Dual mutants are capable of singing suggesting that these mutations affect song minimally compared to flight. Moreover, unlike FLN, none of these mutations affect interpulse interval, the most critical sexually selected song parameter in Drosophila. Also, in contrary to the known additive effects of Ext and Phos in the Dual mutant on flight wing beat frequency, a subtractive effect on sine song frequency is found in this study. That mutations in MLC2 are manifested differently for song and flight suggest that stretch activation plays a minimal or no role in song production.
The results in this study suggest that the conserved regions of FLN and MLC2 are essential to support underlying IFM contractile structure and function necessary for flight, whereas the fast evolving FLN N-terminal region optimizes IFM's biological performance in flight and species-specific song possibly under positive selection regime.
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Päällysaho, S. (Seliina). "Contribution of X chromosomal and autosomal genes to species differences in male courtship songs of the Drosophila virilis group species." Doctoral thesis, University of Oulu, 2001. http://urn.fi/urn:isbn:9514265831.
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Abstract
In sympatric Drosophila species, songs produced by male wing
vibration during courtship are an effective mechanism preventing interspecific
matings and maintaining sexual isolation between different species. These songs
can vary greatly even between closely related species. The aim of this study was
to localise X chromosomal and autosomal genes affecting species differences in
male courtship song and to study their interaction in the D.
virilis group species. Various genes were probed by in
situ hybridisation on the X chromosomes of six species of the group,
which enabled us to use localised RFLP markers in QTL studies, as well as to
compare gene arrangements of different species.
Genetic analyses of differences between the songs of D.
virilis and D. littoralis showed that
species-specific song traits are affected both by X chromosomal and autosomal
genes. The X chromosomal gene(s) having a major impact on pause and pulse length
in male song were found to be located at the proximal region of the chromosome.
Precise localisation of the song genes was, however, not possible due to multiple
chromosome rearrangements restricting recombination between RFLP markers located
on this area. The same problem was faced when studying hybrids between
D. flavomontana and D. montana with
less diverged X chromosomal gene arrangements.
Interaction between the X chromosomal and autosomal song genes in determining
male song traits was studied in four species belonging to the
virilis and montana phylads of
D. virilis group. The long pauses in courtship song were
found to be mainly caused by X chromosomal song genes (or maternal / cytological
factors), while pulse length was determined by X chromosomal genes interacting
with autosomal genes. This confirms the important role of X chromosomal gene(s)
in song evolution in the montana phylad species. The
direction of dominance in hybrid songs suggests that the songs of the
montana phylad species have been affected by directional
selection favouring shorter pulses and longer pauses between sound pulses during
their evolution.
The levels and patterns of DNA polymorphism in an X-linked
fused (fu) gene was studied in
different D. montana populations. These studies revealed
that D. montana populations are significantly but not
completely isolated, and that a selective sweep at fu (or at
a gene linked to fu) may be the reason for the reduced
levels and patterns of variability of this gene in Finnish D.
montana populations. The methods used in this study will be utilized
to study variation in 'song genes' in the future.
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Delcourt, Matthieu. "The Quantitative Genetics of Good Genes: Fitness, Male Display, and Female Preference." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20311.
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The ultimate goal of my thesis is to develop a better understanding of the contribution of indirect benefits (i.e. good genes) to the evolution of female mate preferences. It is genetic variance in, and genetic correlations (covariances) among, male sexual displays, female preferences for them, and fitness that in part determine the degree to which females preferring certain male displays over others will gain an indirect benefit by having higher fitness offspring. Recent advances in quantitative genetic theory provide the mathematical means for quantifying the strength of indirect selection for female mate preferences (Kirkpatrick and Hall 2004), at least under certain conditions, but there are few empirical systems for which such data exist (Brooks and Endler 2001; Qvarnström et al. 2006). I have undertaken a classic half-sibling breeding design with the ultimate goal of estimating the specific parameters of this model in a population of the Australian fruit fly Drosophila serrata. The breeding design was performed across two environments - one to which the population was well adapted and a novel environment to which it was not - thereby also providing insight into genotype-by-environment interactions for this suite of traits and their effects on good genes indirect benefits in a novel environment. General insight is also gained into the genetic covariance of male and female fitness and the prevalence of intralocus sexual conflict, the quantitative genetic basis of female mate preferences for multiple male traits, the condition-dependence of these traits, and the genetic association between sexual displays and fitness when mutation-selection balance is inferred. My results advocate caution in the application of existing theory to quantify the strength of indirect selection, suggesting that a good genes process may be fundamentally different when the exaggeration of sexual displays is eventually halted and an equilibrium is reached between opposing selection.
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Friberg, Urban. "Sexual conflict and male-female coevolution in the fruit fly." Doctoral thesis, Umeå : Department of Ecology and Environmental Science, Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-735.
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Sun, Sha. "Functional analysis of the hybrid male sterility gene Odysseus in Drosophila /." 2003. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3108115.
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Price, Catherine S. C. "Sperm precedence and the evolution of cryptic reproductive isolation between species of Drosophila /." 1999. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:9934108.
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Chen, Yu-Hui, and 陳昱暉. "WIDE AWAKE modulates male-male courtship in Drosophila." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/35169669573968143477.
Full textAbstract:
碩士國立暨南國際大學
應用化學系
104
Animals present several sensory cues to identify the same species and suitable partner for reproduction. Courtship, an instinct of animals in the nature, normally occurs in between opposite sexes. Interestingly, a lot of researches proved that courtship and sexual behaviors existed between the same sexes in many species, but the cellular or molecular mechanism is not clear. In this study, I demonstrate the existence of functional WIDE AWAKE (WAKE) and their acute requirement for inhibiting inter-male courtship in the neuronal system of adult Drosophila. I showed that hypomorphic mutants of the essential wake gene on both partners cause male-male courtship behavior, and can be rescued in either the wake heterozygous courter, or the courtee. Consistently, the knocking down of WAKE by expressing UAS-RNAiwake under an RU486-inducible pan-neuronal driver (elav-GeneSwitch) also caused inter-male courtship behavior. Interestingly, the WAKE may modulate the GABAA receptor Resistant to Dieldrin (Rdl) levels for inhibiting male-to-male courtship. These data explicitly demonstrate the involvement of wake in Drosophila inter-male courtship behavior and may lead to important advances in the understanding in vertebrates.
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Kuo, Shu-Yun, and 郭書昀. "High Sex Drive Induced Male Courtship Homosexuality in Drosophila." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/c4t7d4.
Full textAbstract:
碩士國立暨南國際大學
應用化學系
101
Courtship behavior is a kind of instinct on natural animals. By courting to female, male can mate and most of all multiply their descendants. In some species, courting with homo sex are not uncommon but the molecular mechanisms are poorly known. Drosophila provides appropriate genetic tools and the advantage of large-scale analyses for research. Normally, homosexual courtship behavior seldom occurs among Drosophila; genetic manipulation could largely enhance the occurrence of the behavior. Dopamine (DA) has been proven to participate in the sexual desire control of mammals. Interestingly, increased DA level in Drosophila enhances male –male courtship behavior. In our research found that overexpress dopamine level on a specific dopaminergic neurons which innervate the calyx of mushroom bodies (Mbs), enhance the male courtship strength. Similarly, in our research found that it not only enhances male-female courtship behavior but also increased male-male courtship behavior. We also show that male-male courtship behavior is visual cue dependent and it does not change sexual preference. Interestingly, under the condition of visual deprivation, increased dopamine level on specific dopaminergic neurons, fly shows significant male-male courtship behavior toward the fly with dopamine level decreased on specific dopaminergic neurons. Our results show that with simply controlled this neuron circuit will affect sexuality of fly and lead to male-male courtship behavior. The outcome may provide an effective platform for relevant research on sexual activity.
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Chiu, Hui. "Neural Control of Male and Female Aggression in Drosophila." Thesis, 2021. https://thesis.library.caltech.edu/14170/2/Hui_Chiu_BBE_Thesis_v5_210517.pdf.
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Aggression is essential for an individual’s survival, but it can also lead to unfavorable consequences when misregulated. It is thus important to study the neural basis of this behavior not only for learning how the nervous system is constructed to generate an innate behavior but also for finding the causality of misregulation. Although many circuit and molecular mechanisms underlying aggression have been revealed, our knowledge is mostly restricted to males. Given that sexual differences in aggression are seen in most if not all species, the mechanisms that we learned in one sex may not be directly applied to the other. Therefore, studying the neural basis of aggression in both sexes is necessary for gaining a full understanding of this behavior. Drosophila serves as a unique model for such studies because males and females differ not only in the level of aggressiveness but also in the motor patterns. Interestingly, the aggression-promoting neurons that have been identified so far are mostly sex-specific, raising the possibility that males and females adopt distinct circuits for controlling aggression. However, many sexually shared features of aggression also imply the existence of common circuit elements. My thesis work investigated whether any aggression circuit modules are shared by the two sexes and how the circuit is organized to generate sexually shared and dimorphic motor patterns. Through a behavioral screen and the genetic intersection approach, we identified a pair of sexually shared neurons, CAP, that regulates aggressive approach in both sexes, as well as a pair of male-specific neurons, MAP, whose activation promotes the transition from approach to male-specific attack. We subsequently identified the female homologue, fpC1 neurons, whose activation induces female aggression. Supported by the in vivo imaging and the behavioral epistasis results, we confirmed the functional connectivity between CAP and MAP/fpC1 in males and females, respectively. Lastly, we showed that the connectivity between CAP and MAP/fpC1 is strengthened in socially isolated flies, which exemplifies how circuits can be modified by social isolation to enhance aggression in both sexes. The connectivity between CAP and MAP/fpC1 provides a circuit logic for the control of sexually shared and dimorphic aggressive behaviors. It can be used as an entry point for circuit mapping as well as for further investigation of mechanisms underlying sexual differences in aggression.
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Huang, Jiun-Yuan, and 黃鈞源. "Functional dissection of dopaminergic neurons underlying male-male courtship behavior in Drosophila." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/37493002961579082540.
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碩士國立暨南國際大學
生物醫學科技研究所
98
Courtship behavior is fundamental to the propagation of animal species. Animals use multiple sensory cues to recognize conspecifics and to choose a potentially suitable mate for reproduction. A courtship behavior occurs in heterosexual usually. The recent study found that sexual behavior between males is observed in many species, but the biological factors involved are poorly known. Although wild-type male flies rarely show male–male courtship, the frequency and intensity of this behavior can be strongly increased by genetic manipulation. Dopamine (DA) is a very important neuromodulator in animals. Its role in mammal heterosexual behavior has been extensively studied. Studies demonstrate that DA elevation can enhance male-male courtship behavior in Drosophila. We used genetic approach to increasing dopamine level by UAS-TH under a driver of Murashka-1 and showed enhanced propensity to court other males but did not change their courtship toward virgin females and locomotor activity. Consistently, the knocking downs of dopamine by UAS-THi under a same driver of Murashka-1 and investigated increased male attractiveness or decrease aversiveness towards other males in dark. Our results show that the Murashka-1 expressing neurons played an important role in the regulation of the promotion of male courtship among fruit flies homosexual behavior among the production.
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Chiang, Cheng-Ta, and 江政達. "Male pheromonal role in reproductive isolation between Drosophila melanogaster races." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/35239007431609299007.
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碩士國立清華大學
分子與細胞生物研究所
94
Pheromonal cuticular hydrocarbons have been shown to play important roles in species recognition and sexual isolation. A high correlation between female cuticular hydrocarbons and differentiation of mating behavior was observed in Drosophila melanogaster. However, the role of the male cuticular hydrocarbons in this sexual isolation remains elusive. In this study, male cuticular hydrocarbons not only diverged between Z and M races, but also within Z race (namely ZA and ZB groups). Females from ZA group prefer to mate with males carrying Z male cuticular hydrocarbons indicating that the importance of the male cuticular hydrocarbons in sexual isolation. On the other hand, females from ZB group prefer to mate with Z males, but mating success of Z males carrying Z or M male cuticular hydrocarbons is similar. Genetic mapping by using chromosome substitution lines showed that the production of the male pheromonal signal is mainly controlled by the third chromosome. Several cuticular hydrocarbon candidates for ZA females preference, including 7T, 5T, 25Br, 7P, and 5P, were suggested by combining the results of behavioral experiments and cuticular hydrocarbons variation analysis. My study provides the first evidence demonstrating that male cuticular hydrocarbon changes are one of the key switches in racial differentiation. Evolutionary forces shaping female preferences might uncover in the near feature.
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Latham, Kristin Lynn. "Regulation by male-specific fruitless of neural circuitry used during courtship and copulation behavior in Drosophila melanogaster." Thesis, 2005. http://hdl.handle.net/1957/28943.
Full textAbstract:
Courtship and copulation behaviors in Drosophila melanogaster males are
regulated by sex-specific products from the gene fruitless (fru). Male-specific FRU
proteins (FRU[superscript M]) are putative transcription factors of the BTB-ZnF family that likely
act by controlling development and maintenance of the neural circuitry used during
male sexual behavior. However, which neuronal characteristics are regulated by
FRU[superscript M] is mostly unknown and how FRU[superscript M] neurons are grouped into circuits and the
role that specific neuronal circuits play in sexual behavior has not been elucidated. I
have identified a subset of FRU[superscript M] neurons that co-express the transcription factor,
Engrailed (En). After fru[superscript M]-RNAi-induced targeted removal of FRU[superscript M] proteins from
FRU[superscript M]/En neurons, males were impaired in their ability to initiate or maintain
copulation. Further, I examined two characteristics, the initial projections and
neurotransmitters used by FRU[superscript M]/En neurons. Males and females showed a difference
in the neurochemistry of FRU[superscript M]/En neurons in the thoracic ganglia; this
neurochemistry is disrupted in fru mutant males.
For one cohort of serotonergic neurons in the abdominal ganglion that were
previously shown to be dependent on FRU[superscript M] for expression of serotonin, I determined
that FRU[superscript M] works in conjunction with other sex-specific genes, TAKEOUT (TO) and
DOUBLESEX (DSX), to induce of serotonin expression in males; in females
serotonin expression is repressed by DSX and TO.
Finally, I performed a genetic screen for genes that interact with, or are
downstream targets of, fru, dsx, or dissatisfaction (dsf). I assessed fertility, copulation
success, and abdominal muscle development of EMS-mutagenized flies, resulting in
one fly line in which homozygous mutant animals had a novel muscle phenotype. By
genetic tests, the mutation was found to be allelic to string, which encodes a Cdc25-
like phosphatase.
Taken together, my research demonstrates that subsets of FRU[superscript M] neurons
function in circumscribed circuits to regulate specific portions of sexual behavior, and
that FRU[superscript M], along with other sex-specific genes, controls development of these
neurons in part by determining neurochemistry. Further, FRU[superscript M] likely directs multiple
downstream targets, in different subsets of neurons in which it is expressed, which
collectively provide correct development of neural circuits underlying courtship and
copulation behavior.Graduation date: 2006
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Tsai, Jui-He. "Studies on the mechanism of homolog pairing in Drosophila male meiosis." 2011. http://trace.tennessee.edu/utk_graddiss/1135.
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Drosophila male is an example of achiasmatic meiosis which lacks crossingover and chiasmata during meiosis. Previous studies showed that homologous pairing of both euchromatin and centromeres is lost during middle prophase I, however, homologs are still connected as they form bivalents. The X-Y pair utilizes a specific repeated sequence within the heterochromatic ribosomal DNA blocks as a pairing site. No pairing sites have yet been identified for the autosomes. To search for such sites, we utilized probes specifically targeting heterochromatin regions to assay pairing sequences and behavior in meiosis by fluorescence in situ hybridization (FISH). We found that the fourth homologs pair at the heterochromatic region 61 and associate with the X chromosome throughout prophase I. The pairing of the fourth homologs is disrupted in the homolog conjunction complex mutants. Conversely, six tested heterochromatic regions of the major autosomes (second and third chromosomes) have proved to be largely unpaired after early prophase I. This suggests that pairing mechanism of the major autosomes may differ from the sex and fourth chromosomes; stable connections between major autosomal homologs might occur at different sites along chromosomes in different cells by analogy to chiasmata. Moreover, FISH analysis also revealed two distinct patterns of sister chromatid cohesion in heterochromatin: regions with stable cohesion and regions lacking cohesion, suggesting that sister chromatid cohesion is incomplete within heterochromatin but with preferential sites in male meiosis.Modifier of Mdg4 in Meiosis (MNM) and Stromalin in Meiosis (SNM) are components of homolog conjunction complex and essential for homolog pairing and segregation in male meiosis. Using yeast two-hybrid assay and co-immunoprecipitation, we showed that the MNM and SNM interact with each other. Specifically, the BTB domain of MNM is responsible for the interaction with SNM, whereas FLYWCH domain of MNM is crucial for this interaction but does not directly interact with SNM. Additionally, point mutation analysis revealed that L9K replacement of the BTB domain weakened the MNM-SNM interaction and caused high frequencies of chromosome nondisjunction. In conclusion, these results provide a biochemical basis for the mechanism of homolog pairing and support the role of homolog conjunction complex in male meiosis.
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Goldbach, Philip Daniel. "Anillin Stabilizes Membrane-cytoskeleton Interactions During Drosophila Male Germ Cell Cytokinesis." Thesis, 2011. http://hdl.handle.net/1807/27580.
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The scaffolding protein anillin plays a crucial role during cytokinesis – the physical separation of daughter cells following chromosome segregation. Anillin binds filamentous F-actin, non-muscle myosin II and septins, and in cell culture models has been shown to restrict actomyosin contractility to the cleavage furrow. Whether anillin also serves this function during the incomplete cytokinesis that occurs in developing germ cells has remained unclear. Localization of anillin to several actin-rich structures in developing male germ cells also suggests potential roles for anillin outside of cytokinesis. In this study, I demonstrate that anillin is required for cytokinesis in dividing Drosophila spermatocytes. In addition, spermatid individualization is defective in anillin-depleted cells, although similarities to another cytokinesis mutant, four wheel drive, suggest this may be a secondary effect of failed cytokinesis. Anillin, septins and myosin II stably associate with the cleavage furrow in wild-type dividing spermatocytes. Anillin is necessary for recruitment of septins to the cleavage furrow, and for maintenance of Rho, F-actin and myosin II at the equator in late stages of cytokinesis. Membrane trafficking appears unaffected in anillin-depleted cells, although, unexpectedly, ectopic expression of one membrane trafficking marker, DE-cadherin-GFP, suppresses the cytokinesis defect. DE-cadherin-GFP recruits β-catenin (armadillo) and α-catenin to the cleavage furrow and stabilizes F-actin at the equator. Taken together, my results suggest that the anillin-septin and cadherin-catenin complexes can serve as alternative means to promote tight physical coupling of F-actin and myosin II to the cleavage furrow and successful completion of cytokinesis.
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Levesque, Lisa. "Identification of genes and gene pathways affecting fertility in male Drosophila." 2010. http://hdl.handle.net/1993/3926.
Full textAbstract:
Drosophila females remate generating an opportunity for sperm competition. Normally the second male to mate sires the majority of progeny; however, conspecific sperm precedence is the phenomena whereby the male of the same species as the female fathers the majority of the progeny regardless of mating order. I surveyed D. simulans laboratory strains carrying D. mauritiana P-element insertions (IG lines) for their ability to sire progeny when second to mate. I found significant variation in the proportion of progeny sired by IG lines, with lines showing sperm competitive breakdown (P2< 0.5). I identified two loci that account for conspecific sperm precedence between D. simulans and D. mauritiana. 81 candidate genes were identified and narrowed down the list on the basis of differences in male reproductive tract gene expression to five (P< 0.05) or eight (P<0.1) genes. A larger concentration of differentially regulated genes within the 89B position was found. Using coding sequence data I identified 10 genes as candidate conspecific male precedence genes. Genes in the 89B region come to light as candidates for future functional studies of conspecific male precedence.