Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703.
Proc Natl Acad Sci U S A. 2013 Oct 22;110(43):17420-5. doi: 10.1073/pnas.1220018110. Epub 2013 Oct 7.
Across animal taxa, seminal proteins are important regulators of female reproductive physiology and behavior. However, little is understood about the physiological or molecular mechanisms by which seminal proteins effect these changes. To investigate this topic, we studied the increase in Drosophila melanogaster ovulation behavior induced by mating. Ovulation requires octopamine (OA) signaling from the central nervous system to coordinate an egg's release from the ovary and its passage into the oviduct. The seminal protein ovulin increases ovulation rates after mating. We tested whether ovulin acts through OA to increase ovulation behavior. Increasing OA neuronal excitability compensated for a lack of ovulin received during mating. Moreover, we identified a mating-dependent relaxation of oviduct musculature, for which ovulin is a necessary and sufficient male contribution. We report further that oviduct muscle relaxation can be induced by activating OA neurons, requires normal metabolic production of OA, and reflects ovulin's increasing of OA neuronal signaling. Finally, we showed that as a result of ovulin exposure, there is subsequent growth of OA synaptic sites at the oviduct, demonstrating that seminal proteins can contribute to synaptic plasticity. Together, these results demonstrate that ovulin increases ovulation through OA neuronal signaling and, by extension, that seminal proteins can alter reproductive physiology by modulating known female pathways regulating reproduction.
在动物分类中，精液蛋白是调节雌性生殖生理和行为的重要调节剂。然而，对于精液蛋白如何影响这些变化的生理或分子机制知之甚少。为了研究这个课题，我们研究了交配诱导的黑腹果蝇排卵行为的增加。排卵需要来自中枢神经系统的章鱼胺 (OA) 信号来协调卵子从卵巢释放并进入输卵管。精液蛋白 ovulin 在交配后增加排卵率。我们测试了 ovulin 是否通过 OA 发挥作用来增加排卵行为。增加 OA 神经元兴奋性可以弥补交配期间缺乏 ovulin 的情况。此外，我们确定了一种交配依赖性的输卵管肌肉松弛，而 ovulin 是雄性必需且充分的贡献。我们进一步报告说，输卵管肌肉松弛可以通过激活 OA 神经元来诱导，需要 OA 的正常代谢产生，并且反映了 ovulin 增加 OA 神经元信号。最后，我们表明，由于暴露于 ovulin，随后在输卵管中出现 OA 突触部位的生长，表明精液蛋白可以通过调节已知的女性生殖通路来促进突触可塑性。总之，这些结果表明 ovulin 通过 OA 神经元信号增加排卵，并且，精液蛋白可以通过调节已知的女性生殖通路来改变生殖生理。
