Vertical transmission of mosquito microbiota in a closed system

The mosquito gut microbiota influences its ability to transmit harmful viruses and parasites. Accordingly, manipulating mosquito gut microbiota is a promising avenue of reducing mosquito-borne human pathogen transmission. A successful microbial control campaign will require a thorough understanding of how bacteria are transmitted thorough a mosquito population and how transmission varies between individuals. Through two parallel but complementary studies using the yellow fever mosquito Aedes aegypti as a focal host species, we surveyed vertical transmission of bacteria from individual mothers to cohorts of offspring in a closed system. We found that laboratory-derived and field-collected mothers deposit bacteria that support offspring development, and that variation in microbiota composition correlated with offspring fitness. Maternally transmitted bacteria were detected in both larval and adult offspring, although the relative abundances of specific taxa differed between life stages. Microbiota composition in adult offspring closely resembled microbiota composition in their respective mothers, but there was considerable variability in microbiome composition across both individual mothers from the same laboratory or field population and individual offspring from a single mother reared in a closed system. Overall, our results demonstrate the vertical transmission of mosquito-associated microbiota across generations, including bacterial taxa that could potentially be leveraged for mosquito and mosquito-borne disease control.