Female remating and sperm use in Drosophila buzzatii and D. koepferae

JUAN HURTADO; ESTEBAN HASSON

Belem

Simposio; VII Simpósio de Ecologia, Genética e Evolução de Drosophila.; 2011

During mating, males transfer to females diverse molecules that exert potent effects on female physiology and behavior. These molecules interact with proteins of the female reproductive tract which serves as the arena for postmating sexual selection. This cryptic sexual selection is believed to govern a rapid evolution of reproductive proteins. Since female remating is a prerequisite for sperm competition and cryptic female choice, postmating interactions should further increase in complexity in polyandrous species. In this sense, comparing female remating and sperm use between related species will help to elucidate the causal mechanisms and biological consequences of the rapid evolution of reproductive proteins. We compared female remating frequency and sperm use over time between Drosophila buzzatii and D. koepferae, two sinmorphic species of the repleta group. D. buzzatii females recovered remating frequency faster and depleted stored sperm slower than D. koepferae. These interspecific differences reveal higher chances for ejaculate-ejaculate interactions in D. buzzatii suggesting more complex postmating interactions. In addition, intraspecific comparisons among different strains showed that genetic variability for female remating is explained by both males and females in D. koepferae but only by females in D. buzzatii.