A mating plug protein reduces early female remating in Drosophila melanogaster.
ABSTRACT Mating plugs are formed within the female reproductive tract during mating from male ejaculate constituents or even from male genitalia themselves. Across species, mating plugs have roles in sperm storage and the prevention of female remating. In the fruitfly Drosophila melanogaster, accessory gland proteins such as the sex peptide are known to reduce female remating, however this effect can take some time to establish, hence other ejaculate components must also be involved. We hypothesised a role for the PEBII mating plug protein in the prevention of early female remating. Using RNA interference we produced PEBII knockdown males. We found that these males were significantly less able to prevent female remating in the 4h following mating. The mating plugs produced by PEBII knockdown males also showed lower levels of autofluorescence in the first 10min after the start of mating, suggesting they differed in composition to those of control males. Reduced levels of PEBII had no effect, however, on fecundity, progeny production or egg-adult viability in the first 24 after mating, suggesting there were no short-term effects of PEB II on sperm transfer, storage or use. Our results show that PEBII has a subtle but significant role in the prevention of early female remating.
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ABSTRACT: Among most animals with internal fertilization, females store sperm in specific regions of their reproductive tract for later use. Sperm storage enables prolonged fertility, physical and temporal separation of mating from fertilization and, when females mate with multiple males, opportunities for differential use of the various males' sperm. Thus, stored sperm move within the female reproductive tract as well as to several potential fates - fertilization, displacement by other sperm or ejection by the female. Drosophila melanogaster is a leading model system for elucidating both the mechanisms and evolutionary consequences of female sperm storage and differential male fertilization success. The prominence of Drosophila is due, in part, to the ability to examine processes influencing sperm movement and fate at several biological levels, from molecules to organ systems. In this review, we describe male and female factors, as well as their interactions, involved in female sperm storage and differential male fertilization success.Spermatogenesis. 07/2012; 2(3):224-235.
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ABSTRACT: Proteins in the seminal fluid of animals with internal fertilization affect numerous responses in mated females that impact both male and female fertility. Among these proteins is the highly represented class of proteolysis regulators (proteases and their inhibitors). Though proteolysis regulators have now been identified in the seminal fluid of all animals in which proteomic studies of the seminal fluid have been conducted (as well as several other species in which they have not), a unified understanding of the importance of proteolysis to male fertilization success and other reproductive processes has not yet been achieved. In this review, we provide an overview of the identification of proteolysis regulators in the seminal fluid of humans and Drosophila melanogaster, the two species with the most comprehensively known seminal fluid proteomes. We also highlight reports demonstrating the functional significance of specific proteolysis regulators in reproductive and post-mating processes. Finally, we make broad suggestions for the direction of future research into the roles of both active seminal fluid proteolysis regulators and their inactive homologs, another significant class of seminal fluid proteins. We hope that this review aids researchers in pursuing a coordinated study of the functional significance of proteolysis regulators in semen. Mol. Reprod. Dev. © 2012 Wiley Periodicals, Inc.Molecular Reproduction and Development 10/2012; · 2.81 Impact Factor
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ABSTRACT: Innate behaviors are often executed in concert with accompanying physiological programs. How this coordination is achieved is poorly understood. Mating behavior and the transfer of sperm and seminal fluid (SSFT) provide a model for understanding how concerted behavioral and physiological programs are coordinated. Here we identify a male-specific neural pathway that coordinates the timing of SSFT with the duration of copulation behavior in Drosophila. Silencing four abdominal ganglion (AG) interneurons (INs) that contain the neuropeptide corazonin (Crz) both blocked SSFT and substantially lengthened copulation duration. Activating these Crz INs caused rapid ejaculation in isolated males, a phenotype mimicked by injection of Crz peptide. Crz promotes SSFT by activating serotonergic (5-HT) projection neurons (PNs) that innervate the accessory glands. Activation of these PNs in copulo caused premature SSFT and also shortened copulation duration. However, mating terminated normally when these PNs were silenced, indicating that SSFT is not required for appropriate copulation duration. Thus, the lengthened copulation duration phenotype caused by silencing Crz INs is independent of the block to SSFT. We conclude that four Crz INs independently control SSFT and copulation duration, thereby coupling the timing of these two processes.Proceedings of the National Academy of Sciences 11/2012; · 9.81 Impact Factor