Mating activates transcriptional programs and represses microRNAs in the Drosophila melanogaster female reproductive tract [miRNA-seq]

The female’s reproductive tract is exposed directly to the male’s ejaculate, making it a hotspot for mating-induced responses shortly after mating. In Drosophila melanogaster, changes in the reproductive tract are essential to optimize fertilization. To detect the earliest gene regulatory events that underlie these changes, we measured transcript abundances using RNA-seq and microRNA-seq of reproductive tracts of unmated females and females collected within 10-15 minutes after the end of mating, either to a wildtype male or to a male with defective BMP signaling in secondary cells of the accessory gland, which influences the composition of the male’s ejaculate. We observed transcript abundance changes for genes with roles in tissue morphogenesis, wound healing, the immune response and metabolism. Strikingly, predicted targets of microRNAs that respond to mating are enriched for overlapping functions, suggesting that mating-induced changes are in part regulated by microRNAs. Most of the differentially expressed RNAs are upregulated in response to mating, while most of the differentially expressed microRNAs are downregulated. This pattern suggests a response of activation and de-repression of gene programs that switch the reproductive tract to a “mated” state, rather than a repression of virgin-specific programs. Male genotype did not influence transcript levels, indicating that the earliest transcriptomic responses in the reproductive tract are not dependent on ejaculate components that require BMP signaling in secondary cells. Our results shed light on the molecular changes that accompany very early responses to mating and present candidate genes and microRNAs that can be further examined for their participation in alterations of the reproductive tract microenvironment in response to signals from the male. RNA-seq and microRNA-seq was done on the reproductive tracts of unmated D. melanogaster females, and on females mated to control males or mated to males with inhibited BMP signaling in the secondary cells of their accessory glands. Females were collected for reproductive tract dissections within 10-15 minutes after the end of mating. 3 biological replicates were collected for each treatment.