Title: Sperm Utilization in Once- and Twice-Mated Drosophila pseudoobscura Females
Abstract:We investigated the effect of single mating and remating on sperm utilization in Drosophila pseudoobscura females. Once-mated females produced progeny at a high level for 15 days; thereafter the numbe...We investigated the effect of single mating and remating on sperm utilization in Drosophila pseudoobscura females. Once-mated females produced progeny at a high level for 15 days; thereafter the number dropped significantly. Seventy-two percent of the females remated within 6 days after the initial mating, when approximately 30% of the sperm was utilized. Thus, D. pseudoobscura females remate before sperm supply is exhausted. Remated females produced more progeny than once-mated females, regardless of the genotype of males involved in matings. The increase occurred shortly after remating and thereafter diminished to the same level as that of once-mated females. Sperm competition was evident when the two male mates were of different genotype. The mean sperm displacement ability of ST;or/males was .67 and for AR; + / + males .90. The two means were not statistically significant. In each case, however, sperm displacement was evident.Read More