Experimental evolution under hyper-promiscuity in Drosophila melanogaster

BMC Evolutionary Biology

Research Article

Stuart Wigby¹  Jennifer C. Perry²  Jacek Radwan³  Nina Wedell⁴  David J. Hosken⁴  Richa Joag⁵ 

[1] Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK;Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK;Jesus College, University of Oxford, Oxford, UK;Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland;University of Exeter, Penryn, UK;University of Exeter, Penryn, UK;Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland;

关键词: Copulation;    Courtship;    Drosophila melanogaster;    Ejaculate;    Experimental evolution;    Mating;    Sex peptide;    Sexual selection;    Sperm competition;   

DOI  :  10.1186/s12862-016-0699-8

 received in 2015-10-23, accepted in 2016-06-05,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundThe number of partners that individuals mate with over their lifetime is a defining feature of mating systems, and variation in mate number is thought to be a major driver of sexual evolution. Although previous research has investigated the evolutionary consequences of reductions in the number of mates, we know little about the costs and benefits of increased numbers of mates. Here, we use a genetic manipulation of mating frequency in Drosophila melanogaster to create a novel, highly promiscuous mating system. We generated D. melanogaster populations in which flies were deficient for the sex peptide receptor (SPR) gene – resulting in SPR- females that mated more frequently – and genetically-matched control populations, and allowed them to evolve for 55 generations. At several time-points during this experimental evolution, we assayed behavioural, morphological and transcriptional reproductive phenotypes expected to evolve in response to increased population mating frequencies.ResultsWe found that males from the high mating frequency SPR- populations evolved decreased ability to inhibit the receptivity of their mates and decreased copulation duration, in line with predictions of decreased per-mating investment with increased sperm competition. Unexpectedly, SPR- population males also evolved weakly increased sex peptide (SP) gene expression. Males from SPR- populations initially (i.e., before experimental evolution) exhibited more frequent courtship and faster time until mating relative to controls, but over evolutionary time these differences diminished or reversed.ConclusionsIn response to experimentally increased mating frequency, SPR- males evolved behavioural responses consistent with decreased male post-copulatory investment at each mating and decreased overall pre-copulatory performance. The trend towards increased SP gene expression might plausibly relate to functional differences in the two domains of the SP protein. Our study highlights the utility of genetic manipulations of animal social and sexual environments coupled with experimental evolution.

【 授权许可】

CC BY   
© The Author(s). 2016