Strain-dependent differences in several reproductive traits are not accompanied by early postmating transcriptome changes in female Drosophila melanogaster.

Upon mating, Drosophila melanogaster females undergo numerous alterations in their behavior and reproductive physiology that are accompanied by small-magnitude transcript-level changes in up to 1700 genes. Many of these postmating transcriptome changes are the direct result of the sperm and seminal fluid proteins (Acps) that females receive from their mates. To begin to determine if the genetic background of the female's mate contributes to the previously described gene expression changes, we assessed whether interactions between the genotypes of two commonly used laboratory strains of D. melanogaster (Canton-S and Oregon R) influence the female's postmating transcriptome as well as several pre- and postcopulatory phenotypes. We find negligible differences in the female's transcriptome at 1-3 hr postmating regardless of the strain of the male with whom she mated. However, a male x female genotype interaction significantly influenced mate selection, and, in some cases, fecundity, fertility, and hatchability. Our data support previous work suggesting that many of the early postmating changes observed in D. melanogaster females are not caused by large modifications of transcript levels. Instead, early postmating phenotypes result from preexisting receptors or pathways that are already in place upon sexual maturity.