Transcriptome of germ-free and colonized third instar Aedes aegypti larvae

Mosquitoes require a living microbiota for a conventional larval development. We developed a method to obtain germ-free mosquitoes. It is based on the use of an auxotrophic Escherichia coli strain which requires two non-standard amino acids for its growth. By modulating the presence of such amino acids in the larval culture medium, bacterial colonization can be stopped and germ-free individuals are obtained. We investigated the effect of such decolonization on third-instar Ae. aegypti larvae, by analyzing the transcriptome of germ-free (reversibly colonized) larvae and larvae colonized by the wild-type E. coli strain. We analyzed gene expression in both dissected guts and whole larvae at 12 h and 20 h after decolonization (and molting).