Abstracts (first author)
Sex-specific effects of pathogenic bacterial infection on fitness components, reproductive behaviour and mate choice in Drosophila melanogaster
We investigated the sex specific effect of Serratia marcescens infection through septic injury on two components of fitness, survivorship and adult competitive reproductive fitness in male and female Drosophila melanogaster. Under competitive conditions, infected females showed significantly lower reproductive output compared to control females. However, male reproductive fitness was not affected by infection. We did not find any cost of injury and immune deployment in our study indicating that the fitness cost resulted only from sustained infection or virulence. However, the bacteria was found to be pathogenic, growing equally well in males and females and causing about 80% mortality over an eleven day period with no significant difference in mortality between sexes. Thus, such sex specific effects of pathogens on individual components of fitness indicate that the total fitness cost experienced by each sex might be very different, even within a given regime, thereby affecting the evolution of antibacterial immunity. Given such sex-specific effects of bacterial infection on reproductive fitness, we further, investigated the sex-specific effect of bacterial infection on components of reproductive behaviour. We did not find any change in mating latency or copulation duration with male or female infection status. When given a simultaneous choice between infected and sham infected females, males preferentially mated with sham infected females. This result suggests that male D. melanogaster may adaptively bias their mating effort in response to the infection status of females.