Meeting Abstract

S6-1.3  Jan. 5  Postcopulatory male-female interactions in Drosophila melanogaster: dissecting the female side. LAWNICZAK, Mara*; BEGUN, David; UCL/UCDavis; UCDavis

In Drosophila, what we know about the proteins involved in post-mating interactions is heavily biased towards the male side. Genes important in female-mediation of seminal fluid and sperm (including female effects on the outcome of sperm competition) remain largely undiscovered in spite of the obvious fitness-related phenotypes affected in females by seminal fluid transfer. We used quantitative trait locus (QTL) mapping to identify regions of the genome contributing to female propensity to use first or second male sperm (P2), female refractoriness to re-mating, and early-life fertility. We found several regions of the genome influencing P2, refractoriness, and fertility. We also used Affymetrix whole genome expression microarrays to identify genes differentially expressed between virgin and recently mated females. Genes showing the greatest induction upon mating included several serine proteases. We used molecular population genetic approaches to investigate the history of selection experienced by these mating-induced serine proteases. Evolutionary genetic analyses indicate extremely rapid evolution in several of genes, and interesting patterns of gene duplication and gene loss just within the melanogaster subgroup. Directional selection has been important in the evolutionary history of these genes, similar to several seminal fluid genes, documenting evidence for rapid evolution of female reproduction-related genes in Drosophila.