Socially cued seminal fluid gene expression mediates responses in ejaculate quality to sperm competition risk

Research output: Contribution to journalArticle

22 Citations (Scopus)


There is considerable evidence that males will increase the number of sperm ejaculated in response to sperm competition risk. However, whether they have the capacity to adjust seminal fluid components of the ejaculate has received less attention. Male crickets (Teleogryllus oceanicus) have been shown to adjust the viability of sperm in their ejaculate in response to sperm competition risk. Here we show that socially mediated plasticity in sperm viability is probably due, at least in part, to male adjustments in the protein composition of the seminal fluid. Seven seminal fluid protein genes were found to have an increased expression in males exposed to rival calls. Increased expression of these genes was correlated with increased sperm viability in whole ejaculates, and gene knockdown confirmed that at least one of these proteins promotes sperm viability. Our results lend support for recent theoretical models that predict complex responses inmale allocation to seminal fluid composition in response to sperm competition risk.

Original languageEnglish
Article number20171486
Number of pages8
JournalProceedings of the Royal Society B: Biological Sciences
Issue number1861
Publication statusPublished - 30 Aug 2017

Cite this