Female membrane proteins regulate postmating ovulation in Drosophila melanogaster by ovulin-dependent and-independent pathways

• 成果类型: Article
• 署名作者: Yang, Mengye; White, Melissa A.; Findlay, Geoffrey D.; Vignogna, Ryan C.; Apger-McGlaughon, Jennifer; Clark, Nathan L.; Choi, Jae Young; Fromme, J. Christopher; Wolfner, Mariana F.
• 署名单位: Cornell University; College of the Holy Cross; Cornell University; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; University of Kansas; Cornell University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13307
• DOI: 10.1073/pnas.2508783122
• 发表日期: 2025-09-16
• 关键词: seminal fluid protein; accessory-gland gene; positive selection; male reproduction; acp26aa; EVOLUTION; fertilization; receptor; BEHAVIOR; RECOGNITION

摘要

Ovulation is an intricate process that is essential for reproductive success. In Drosophila melanogaster, ovulation increases after mating. This increase is initiated by the male seminal fluid protein ovulin and is executed by female pathways, including octopamine (OA) neuronal signaling. Despite OA signaling's central role in ovulation regulation, the broader molecular landscape underlying female control of ovulation remains poorly understood. Here, using ovulin as a probe, we performed evolutionary rate covariation and AlphaFold-Multimer prediction screens to identify candidate female ovulation-regulating proteins. Ovulation assays performed on knockdowns or mutants of identified membrane-protein candidates revealed seven important female ovulation regulators: Lgr3, Gabaf3R1, SIFaR, mthl9, Smog, Cirl, and CG6067. Lgr3 and Gabaf3R1 function in an ovulin-dependent manner, while SIFaR and mthl9 regulate ovulation independently of ovulin. For proteins with known nervous system expression, we examined their requirement in OA neurons and their expression in female reproductive tract neurons. Tissue-specific knockdown revealed that Lgr3, Gabaf3R1, SIFaR, and CG6067 act in OA neurons to influence ovulation, highlighting OA neurons as a key signaling hub. Additionally, Lgr3, Gabaf3R1, SIFaR, Smog, and Cirl are expressed in OA neurons innervating the reproductive tract, suggesting a potential local function. Finally, we identified evidence of recurrent positive selection having acted on residues within Smog's ligand binding region, which is interesting in light of ovulin's rapid evolution. Together, these findings significantly expand our understanding of the molecular networks regulating ovulation following mating in Drosophila.