Post-mating expression of female Drosophila melanogaster genomes experimentally evolved under different post-copulatory sexual selection regimes

By combining an experimental evolution approach with genomic techniques, we investigated the effects of seminal fluid on female gene expression. In our study, we experimentally manipulated the mating system in replicate populations of D. melanogaster, by removing post-copulatory sexual selection, with the aim of testing differences in short term post-mating reaction of females evolved under different mating strategies. We show that monogamous females suffer decreased fecundity, regardless of the type of male they were mated with, and that their post-mating gene expression profiles differ significantly from promiscuous females, involving 1141 transcripts (9% of the genes tested). These transcripts are active in several tissues, mainly ovaries, neural tissues, midgut and spermathecae, and are involved in metabolic processes, reproduction and signaling pathways. Our results provide a list of candidate genes responsible for the decrease in female fecundity in the absence of post-copulatory sexual selection, and demonstrate how the female post-mating response can evolve under different mating systems over relatively short time frames.

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