The Drosophila seminal proteome and its role in postcopulatory sexual selection

• Published in: Philosophical transactions of the Royal Society of London. Series B. Biological sciences Vol. 375; no. 1813; p. 20200072
• Main Authors: Wigby, Stuart, Brown, Nora C, Allen, Sarah E, Misra, Snigdha, Sitnik, Jessica L, Sepil, Irem, Clark, Andrew G, Wolfner, Mariana F
• Format: Journal Article
• Language: English
• Published: England The Royal Society 07-12-2020
• Subjects: Review; seminal plasma; sexual conflict; accessory gland; seminal fluid protein; sexual selection; reproduction
• ISSN: 0962-8436; 1471-2970
• DOI: 10.1098/rstb.2020.0072

Postcopulatory sexual selection (PCSS), comprised of sperm competition and cryptic female choice, has emerged as a widespread evolutionary force among polyandrous animals. There is abundant evidence that PCSS can shape the evolution of sperm. However, sperm are not the whole story: they are accompanied by seminal fluid substances that play many roles, including influencing PCSS. Foremost among seminal fluid models is
, which displays ubiquitous polyandry, and exhibits intraspecific variation in a number of seminal fluid proteins (Sfps) that appear to modulate paternity share. Here, we first consolidate current information on the identities of
Sfps. Comparing between
and human seminal proteomes, we find evidence of similarities between many protein classes and individual proteins, including some
Sfp genes linked to PCSS, suggesting evolutionary conservation of broad-scale functions. We then review experimental evidence for the functions of
Sfps in PCSS and sexual conflict. We identify gaps in our current knowledge and areas for future research, including an enhanced identification of PCSS-related Sfps, their interactions with rival sperm and with females, the role of qualitative changes in Sfps and mechanisms of ejaculate tailoring. This article is part of the theme issue 'Fifty years of sperm competition'.