The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Mariana F. Wolfner - One of the best experts on this subject based on the ideXlab platform.
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Long-term interaction between Drosophila Sperm and sex peptide is mediated by other seminal proteins that bind only transiently to Sperm.
Insect Biochemistry and Molecular Biology, 2018Co-Authors: Akanksha Singh, Norene A. Buehner, Kaitlyn J. Baranowski, Geoffrey D. Findlay, Mariana F. WolfnerAbstract:Abstract Seminal fluid proteins elicit several post-mating physiological changes in mated Drosophila melanogaster Females. Some of these changes persist for over a week after mating because the seminal protein that causes these changes, the Sex Peptide (SP), binds to Sperm that are stored in the Female reproductive tract. SP's Sperm binding is mediated by a network of at least eight seminal proteins. We show here that some of these network proteins (CG1656, CG1652, CG9997 and Antares) bind to Sperm within 2 h of mating, like SP. However, while SP remains bound to Sperm at 4 days post-mating, none of the other network proteins are detectable at this time. We also observed that the same network proteins are detectable at 2 h post-mating in seminal receptacle tissue from which Sperm have been removed, but are no longer detectable there by 4 days post-mating, suggesting short-term retention of these proteins in this Female Sperm Storage organ. Our results suggest that these network proteins act transiently to facilitate the conditions for SP's binding to Sperm, perhaps by modifying SP or the Sperm surface, but are not part of a long-acting complex that stably attaches SP to Sperm.
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large neurological component to genetic differences underlying biased Sperm use in drosophila
Genetics, 2013Co-Authors: Clement Y Chow, Mariana F. Wolfner, Andrew G ClarkAbstract:Sperm competition arises as a result of complex interactions among male and Female factors. While the roles of some male factors are known, little is known of the molecules or mechanisms that underlie the Female contribution to Sperm competition. The genetic tools available for Drosophila allow us to identify, in an unbiased manner, candidate Female genes that are critical for mediating Sperm competition outcomes. We first screened for differences in Female Sperm Storage and use patterns by characterizing the natural variation in Sperm competition in a set of 39 lines from the sequenced Drosophila Genetic Reference Panel (DGRP) of wild-derived inbred lines. We found extensive Female variation in Sperm competition outcomes. To generate a list of candidate Female genes for functional studies, we performed a genome-wide association mapping, utilizing the common single-nucleotide polymorphisms (SNPs) segregating in the DGRP lines. Surprisingly, SNPs within ion channel genes and other genes with roles in the nervous system were among the top associated SNPs. Knockdown studies of three candidate genes (para, Rab2, and Rim) in sensory neurons innervating the Female reproductive tract indicate that some of these candidate Female genes may affect Sperm competition by modulating the neural input of these sensory neurons to the Female reproductive tract. More extensive functional studies are needed to elucidate the exact role of all these candidate Female genes in Sperm competition. Nevertheless, the Female nervous system appears to have a previously unappreciated role in Sperm competition. Our results indicate that the study of Female control of Sperm competition should not be limited to Female reproductive tract-specific genes, but should focus also on diverse biological pathways.
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A requirement for the neuromodulators octopamine and tyramine in Drosophila melanogaster Female Sperm Storage
Proceedings of the National Academy of Sciences, 2012Co-Authors: F. W. Avila, M. C. Bloch Qazi, C. D. Rubinstein, Mariana F. WolfnerAbstract:Female Sperm Storage is common among organisms with internal fertilization. It is important for extended fertility and, in cases of multiple mating, for Sperm competition. The physiological mechanisms by which Females store and manage stored Sperm are poorly understood. Here, we report that the biogenic amines tyramine (TA) and octopamine (OA) in Drosophila melanogaster Females play essential roles in Sperm Storage. D. melanogaster Females store Sperm in two types of organs, a single seminal receptacle and a pair of Spermathecae. We examined Sperm Storage parameters in Females mutant in enzymes required for the biochemical synthesis of tyrosine to TA and TA to OA, respectively. Postmating uterine conformational changes, which are associated with Sperm entry and accumulation into Storage, were unaffected by the absence of either TA or OA. However, Sperm release from Storage requires both TA and OA; Sperm were retained in Storage in both types of mutant Females at significantly higher levels than in control flies. Absence of OA inhibited Sperm depletion only from the seminal receptacle, whereas absence of both OA and TA perturbed Sperm depletion from both Storage organ types. We find innervation of the seminal receptacle and Spermathecae by octopaminergic-tyraminergic neurons. These findings identify a distinct role for TA and OA in reproduction, regulating the release of Sperm from Storage, and suggest a mechanism by which Drosophila Females actively regulate the release of stored Sperm.
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a role for acp29ab a predicted seminal fluid lectin in Female Sperm Storage in drosophila melanogaster
Genetics, 2008Co-Authors: Alex Wong, Shannon N Albright, Jonathan D Giebel, Shuqing Ji, Anthony C Fiumera, Mariana F. WolfnerAbstract:Females of many animal species store Sperm for taxon-specific periods of time, ranging from a few hours to years. Female Sperm Storage has important reproductive and evolutionary consequences, yet relatively little is known of its molecular basis. Here, we report the isolation of a loss-of-function mutation of the Drosophila melanogaster Acp29AB gene, which encodes a seminal fluid protein that is transferred from males to Females during mating. Using this mutant, we show that Acp29AB is required for the normal maintenance of Sperm in Storage. Consistent with this role, Acp29AB localizes to Female Sperm Storage organs following mating, although it does not appear to associate tightly with Sperm. Acp29AB is a predicted lectin, suggesting that sugar–protein interactions may be important for D. melanogaster Sperm Storage, much as they are in many mammals. Previous association studies have found an effect of Acp29AB genotype on a male's Sperm competitive ability; our findings suggest that effects on Sperm Storage may underlie these differences in Sperm competition. Moreover, Acp29AB's effects on Sperm Storage and Sperm competition may explain previously documented evidence for positive selection on the Acp29AB locus.
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the developments between gametogenesis and fertilization ovulation and Female Sperm Storage in drosophila melanogaster
Developmental Biology, 2003Co-Authors: Margaret Bloch C Qazi, Yael Heifetz, Mariana F. WolfnerAbstract:Abstract In animals with internal fertilization, ovulation and Female Sperm Storage are essential steps in reproduction. While these events are often required for successful fertilization, they remain poorly understood at the developmental and molecular levels in many species. Ovulation involves the regulated release of oocytes from the ovary. Female Sperm Storage consists of the movement of Sperm into, maintenance within, and release from specific regions of the Female reproductive tract. Both ovulation and Sperm Storage elicit important changes in gametes: in oocytes, ovulation can trigger changes in the egg envelopes and the resumption of meiosis; for Sperm, Storage is a step in their transition from being “movers” to “fertilizers.” Ovulation and Sperm Storage both consist of timed and directed cell movements within a morphologically and chemically complex environment (the Female reproductive tract), culminating with gamete fusion. We review the processes of ovulation and Sperm Storage for Drosophila melanogaster, whose requirements for gamete maturation and Sperm Storage as well as powerful molecular genetics make it an excellent model organism for study of these processes. Within the Female D. melanogaster, both processes are triggered by male factors during and after mating, including Sperm and seminal fluid proteins. Therefore, an interplay of male and Female factors coordinates the gametes for fertilization.
Scott Pitnick - One of the best experts on this subject based on the ideXlab platform.
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Mechanisms underlying the Sperm quality advantage in Sperm competition and cryptic Female choice in Drosophila melanogaster
2014Co-Authors: James M. Pattarini, William T. Starmer, Adam Bjork, Scott PitnickAbstract:Contrary to early predictions of Sperm competition theory, postcopulatory sexual selection favoring increased investment per Sperm (e.g., Sperm size, Sperm quality) has been demonstrated in numerous organisms. Recent findings reveal that Sperm production strategies are highly variable, with males of some species producing relatively few, giant Sperm. We empirically demonstrate for Drosophila melanogaster that both Sperm quality and Sperm quantity independently contribute to competitive male fertilization success. The interaction between Sperm quality and quantity suggests an internal positive reinforcement on selection for Sperm quality, with selection predicted to intensify as investment per Sperm increases and the number of Sperm competing declines. The mechanism underlying the Sperm quality advantage is elucidated through examination of the relationship between Female Sperm-Storage organ morphology and the differential organization of different length Sperm within the organ. Our results exemplify that primary sex cells can bear secondary sexual straits.
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Mechanisms underlying the Sperm quality advantage in Drosophila melanogaster.
Evolution, 2006Co-Authors: James M. Pattarini, William T. Starmer, Adam Bjork, Scott PitnickAbstract:Contrary to early predictions of Sperm competition theory, postcopulatory sexual selection favoring increased investment per Sperm (e.g., Sperm size, Sperm quality) has been demonstrated in numerous organisms. We empirically demonstrate for Drosophila melanogaster that both Sperm quality and Sperm quantity independently contribute to competitive male fertilization success. In addition to these independent effects, there was a significant interaction between Sperm quality and quantity that suggests an internal positive reinforcement on selection for Sperm quality, with selection predicted to intensify as investment per Sperm increases and the number of Sperm competing declines. The mechanism underlying the Sperm quality advantage is elucidated through examination of the relationship between Female Sperm-Storage organ morphology and the differential organization of different length Sperm within the organ. Our results exemplify that primary sex cells can bear secondary sexual straits.
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Ejaculate-Female coevolution in Drosophila mojavensis.
Proceedings of The Royal Society B: Biological Sciences, 2003Co-Authors: Scott Pitnick, Gary T. Miller, Karin Schneider, Therese A. MarkowAbstract:Interspecific studies indicate that Sperm morphology and other ejaculatory traits diverge more rapidly than other types of character in Drosophila and other taxa. This pattern has largely been attributed to postcopulatory sexual selection involving interaction between the sexes. Such divergence has been suggested to lead rapidly to reproductive isolation among populations and thus to be an ‘engine of speciation.’ Here, we test two critical predictions of this hypothesis: (i) there is significant variation in reproductive traits among incipient species; and (ii) divergence in interacting sex–specific traits exhibits a coevolutionary pattern among populations within a species, by examining geographical variation in Drosophila mojavensis , a species in the early stages of speciation. Significant among–population variation was identified in Sperm length and Female Sperm–Storage organ length, and a strong pattern of correlated evolution between these interacting traits was observed. In addition, crosses among populations revealed coevolution of male and Female contributions to egg size. Support for these two important predictions confirms that coevolving internal characters that mediate successful reproduction may play an important part in speciation. The next step is to determine exactly what that role is.
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quantitative genetic analysis of among population variation in Sperm and Female Sperm Storage organ length in drosophila mojavensis
Genetics Research, 2003Co-Authors: Gary T. Miller, William T. Starmer, Scott PitnickAbstract:Summary In Drosophila, Sperm length and the length of the Females’ primary Sperm-Storage organ have rapidly coevolved through post-copulatory sexual selection. This pattern is evident even among geographic populations of Drosophila mojavensis. To understand better these traits of potential importance for speciation, we performed quantitative genetic analysis of both seminal receptacle length and Sperm length in two divergent populations. Parental strains, F1 ,F 1 reciprocal (F1r), F2 ,F 2r, backcross and backcross reciprocal generations were used in a line-cross (generation means) analysis. Seminal receptacle length is largely an autosomal additive trait, whereas additivity, dominance and epistasis all contributed to the means of Sperm length. Either an X-chromosome or a Y-chromosome e!ect was necessary for models of Sperm length to be significant. However, the overall contributions from the X and Y chromosomes to Sperm length was small.
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Functional significance of seminal receptacle length in Drosophila melanogaster
Journal of Evolutionary Biology, 2002Co-Authors: Gary T. Miller, Scott PitnickAbstract:Despite its central role in post-copulatory sexual selection, the Female reproductive tract is poorly understood. Here we provide the first experimental study of the adaptive significance of variation in Female Sperm-Storage organ morphology. Using populations of Drosophila melanogaster artificially selected for longer or shorter seminal receptacles, we identify relationships between the length of this primary Sperm-Storage organ and the number of Sperm stored, pattern of progeny production, rate of egg fertilization, remating interval, and pattern of Sperm precedence. Costs and benefits of relatively short or long organs were identified. Benefits of longer receptacles include increased Sperm-Storage capacity and thus progeny production from a single insemination. Results suggest that longer receptacles have not naturally evolved because of developmental time costs and a correlated reduction in longevity of mated Females. This latter cost may be a consequence of sexual conflict mediated by ejaculate toxicity. Receptacle length did not alter the pattern of Sperm precedence, which is consistent with data on the co-evolution of Sperm and Female receptacle length, and a pattern of differential male fertilization success being principally determined by the interaction between these male and Female traits.
Nicola Hemmings - One of the best experts on this subject based on the ideXlab platform.
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Sperm Gatekeeping: 3D Imaging Reveals a Constricted Entrance to Zebra Finch Sperm Storage Tubules
Biophysical Journal, 2019Co-Authors: Tania Mendonca, Ashley J. Cadby, Nicola HemmingsAbstract:Abstract Females across many internally fertilizing taxa store Sperm, often in specialized Storage organs in their reproductive tracts. In birds, several hundred Sperm Storage tubules exist in the utero-vaginal junction of the oviduct, and there is growing evidence that Sperm Storage in these tubules is selective. The mechanisms underlying Female Sperm Storage in birds remain unknown because of our limited ability to make three-dimensional, live observations inside the large, muscular avian oviduct. Here, we describe a new application of fluorescence selective plane illumination microscopy to optically section oviduct tissue from zebra finch Taeniopygia guttata Females label free by harnessing tissue autofluorescence. Our data provide the first description of the three-dimensional structure of Sperm Storage organs in any vertebrate to the best of our knowledge and reveal the presence of gate-like constricted openings that may play a role in Sperm selection.
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Sperm gatekeeping: 3D imaging reveals a constricted entrance to zebra finch Sperm Storage tubules
bioRxiv, 2018Co-Authors: Tania Mendonca, Ashley J. Cadby, Nicola HemmingsAbstract:Females across many internally fertilising taxa store Sperm, often in specialised Storage organs in their reproductive tracts. In birds, several hundred Sperm Storage tubules exist in the utero-vaginal junction of the oviduct and there is growing evidence that Sperm Storage in these tubules is selective. The nature of the mechanisms underlying Female Sperm Storage in birds remains unknown due to our limited ability to make three dimensional, live observations inside the large, muscular avian oviduct. Here, we describe a new application of fluorescence selective plane illumination microscopy to optically section oviduct tissue from zebra finch Taeniopygia guttata Females label-free, by harnessing tissue autofluorescence. Our data provide the first description of the 3D structure of Sperm Storage tubules in any bird, and reveal the presence of constricted openings to tubules, suggesting active entrapment and release of Sperm.
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differential Sperm Storage by Female zebra finches taeniopygia guttata
Proceedings of The Royal Society B: Biological Sciences, 2017Co-Authors: Nicola Hemmings, T R BirkheadAbstract:When Females mate promiscuously, Female Sperm Storage provides scope to bias the fertilization success towards particular males via the non-random acceptance and utilization of Sperm. The difficult...
Andrea Pilastro - One of the best experts on this subject based on the ideXlab platform.
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Female Sperm Storage mediates post copulatory costs and benefits of ejaculate anticipatory plasticity in the guppy
Journal of Evolutionary Biology, 2020Co-Authors: Gabriela Cardozo, Alessandro Devigili, Pietro Antonelli, Andrea PilastroAbstract:Males of many species evolved the capability of adjusting their ejaculate phenotype in response to social cues to match the expected mating conditions. When Females store Sperm for a prolonged time, the expected fitness return of plastic adjustments of ejaculate phenotype may depend on the interval between mating and fertilization. While prolonged Female Sperm Storage (FSS) increases the opportunity for Sperm competition, as a consequence of the longer temporal overlap of ejaculates from several males, it may also create variable selective forces on ejaculate phenotype, for example by exposing trade-offs between Sperm velocity and Sperm survival. We evaluated the relationship between the plasticity of ejaculate quality and FSS in the guppy, Poecilia reticulata, a polyandrous livebearing fish in which Females store Sperm for several months and where stored Sperm contribute significantly to a male's lifelong reproductive success. In this species, males respond to the perception of future mating opportunities by increasing the quantity (number) and quality (swimming velocity) of ready-to-use Sperm (an anticipatory response called 'Sperm priming'). Here we investigated 1) the effect of Sperm priming on in-vitro Sperm viability at stripping and its temporal decline (as an estimate of Sperm survival), and, 2) the in-vivo competitive fertilization success in relation to Female Sperm Storage using artificial insemination. As expected, Sperm-primed males produced more numerous and faster Sperm, but with a reduced in-vitro Sperm viability at stripping and after 4 hours, compared to their counterparts. Artificial insemination revealed that the small (non-significant) advantage of primed Sperm when fertilization immediately follows insemination, is reversed when eggs are fertilized by Female-stored Sperm, weeks after insemination. By suggesting a plastic trade-off between Sperm velocity and viability, these results demonstrate that prolonged Female Sperm Storage generates divergent selection pressures on ejaculate phenotype.
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Female Sperm Storage mediates postcopulatory costs and benefits of ejaculate anticipatory plasticity in the guppy.
Journal of Evolutionary Biology, 2020Co-Authors: Gabriela Cardozo, Alessandro Devigili, Pietro Antonelli, Andrea PilastroAbstract:Males of many species evolved the capability of adjusting their ejaculate phenotype in response to social cues to match the expected mating conditions. When Females store Sperm for a prolonged time, the expected fitness return of plastic adjustments of ejaculate phenotype may depend on the interval between mating and fertilization. While prolonged Female Sperm Storage (FSS) increases the opportunity for Sperm competition, as a consequence of the longer temporal overlap of ejaculates from several males, it may also create variable selective forces on ejaculate phenotype, for example by exposing trade-offs between Sperm velocity and Sperm survival. We evaluated the relationship between the plasticity of ejaculate quality and FSS in the guppy, Poecilia reticulata, a polyandrous livebearing fish in which Females store Sperm for several months and where stored Sperm contribute significantly to a male's lifelong reproductive success. In this species, males respond to the perception of future mating opportunities by increasing the quantity (number) and quality (swimming velocity) of ready-to-use Sperm (an anticipatory response called 'Sperm priming'). Here we investigated 1) the effect of Sperm priming on in-vitro Sperm viability at stripping and its temporal decline (as an estimate of Sperm survival), and, 2) the in-vivo competitive fertilization success in relation to Female Sperm Storage using artificial insemination. As expected, Sperm-primed males produced more numerous and faster Sperm, but with a reduced in-vitro Sperm viability at stripping and after 4 hours, compared to their counterparts. Artificial insemination revealed that the small (non-significant) advantage of primed Sperm when fertilization immediately follows insemination, is reversed when eggs are fertilized by Female-stored Sperm, weeks after insemination. By suggesting a plastic trade-off between Sperm velocity and viability, these results demonstrate that prolonged Female Sperm Storage generates divergent selection pressures on ejaculate phenotype.
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directional postcopulatory sexual selection is associated with Female Sperm Storage in trinidadian guppies
Evolution, 2016Co-Authors: Alessandro Devigili, Andrea Di Nisio, Alessandro Grapputo, Andrea PilastroAbstract:: Female Sperm Storage (FSS) is taxonomically widespread and often associated with intense Sperm competition, yet its consequences on postcopulatory sexual selection (PCSS) are poorly known. Theory predicts that FSS will reduce the strength of PCSS, because Sperm characteristics favored before and after FSS may be traded-off, and opportunities for nondirectional PCSS should increase. We explored these questions in the guppy (Poecilia reticulata), by allowing Females to mate multiply and by comparing the paternity pattern in two successive broods. Contrary to predictions, the variance in male fertilization success increased after FSS, driven by a change in male paternity share across broods. This change was positively associated with Sperm velocity (measured before FSS) but not with the duration of FSS, indirectly suggesting that faster Sperm were better in entering Female Storage organs, rather than in persisting within them. Other male traits, such as male size and orange color, heterozygosity, and relatedness to the Female, did not influence paternity after FSS. These results indicate that processes associated with FSS tend to reinforce the strength of PCSS in guppies, rather than weaken it. Further work is necessary to test whether this pattern changes in case of more prolonged FSS.
John C Avise - One of the best experts on this subject based on the ideXlab platform.
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high degree of multiple paternity in the viviparous shiner perch cymatogaster aggregata a fish with long term Female Sperm Storage
Marine Biology, 2011Co-Authors: John C AviseAbstract:The Shiner Perch (Cymatogaster aggregata Gibbons) exhibits a viviparous reproductive mode and long-term Female Sperm Storage, two biological features that may predispose this fish species for both intense Sperm competition and frequent multiple paternity within broods. To test these hypotheses, we used polymorphic microsatellite markers to identify sires and quantify paternal contributions to the progeny arrays of 27 pregnant Females from a natural population of C. aggregata. The number of sires per brood ranged from one to eight (mean 4.6), typically with skewed distributions of fertilization success by the fathers but no correlation between sire number and brood size. The extraordinarily high incidences of multiple paternity in this species probably are due in part to high rates of mate encounter, but selection pressures related to the avoidance of maternal–fetal incompatibility may further have promoted the evolution of polyandrous mating behaviors in this Female-pregnant species. Our genetic data are consistent with the hypothesis that viviparity, long-term Sperm Storage, and extreme polyandry are interrelated reproductive phenomena that should promote the evolution of post-copulatory Sperm competition and/or cryptic Female choice in these fishes.
