1st Place: Intergenerational patterns of microbiota acquisition in the yellow fever mosquito, Aedes aegypti

Mosquitoes host diverse communities of bacteria that impact larval development, adult fitness, and the ability of adult females to transmit human pathogens (vector competence). Manipulation of the mosquito microbiome via the introduction of bacteria that reduce mosquito vector competence and/or fitness is a promising avenue for reducing the global burden of mosquito-borne disease. However, the impact of different acquisition routes on microbiome diversity and function in mosquitoes remains under-explored. In this study, we used 16S rRNA gene amplicon sequencing to investigate vertical transmission of mosquito microbiota from mother to offspring and its impact on larval fitness outcomes. We found that microbiota composition in offspring varied greatly, pointing to stochastic transmission of maternal microbes within a population. Relative abundance of the most commonly transmitted bacterial taxa correlated with offspring development outcomes, recapitulating the important role of bacteria in mosquito growth and molting. Correlations between the relative abundance of different bacterial taxa, which varied between different sample types (environment, mother, offspring), further shaped offspring development outcomes, supporting a role for interbacterial competition within the host in mediating mosquito fitness. Altogether, our results have important implications for future efforts to identify bacterial candidates for use in mosquito and/or mosquito-borne disease control.