Elucidating female-specific differentiation genes in the mosquito, Aedes aegypti

Insects account for the vast majority of sexually reproducing animals described and demonstrate significant diversity and complexity in sex-developmental pathways. While only a small number of insect species have had sex-development pathways characterized, orthologues of the master regulator of sex-differentiation, Doublesex (Dsx), have been identified in all insects studied. Using alternative splicing to produce distinct, functional male-specific and femalespecific isoforms, Dsx guides differential gene expression patterns through its activity as a transcription factor. Notably, while male and female specific isoforms contain identical DNAbinding domains, it is expected that sex-specific differences in gene expression are the result of different binding partners at the isoform specific oligomerization domains. The yellow fever mosquito, Aedes aegypti, exhibits pronounced sexual dimorphisms, largely due to the females’ specific need to obtain blood meals. Because of these distinct dimorphic features and its threat to human health, research into Ae. aegypti sex development is of interest to developmental biologists and in the context of public health. Despite numerous studies on Ae. aegypti sex development, little is known about the isoform-specific binding partners of AaeDsx. Using protein pulldown and mass spectrometry techniques, this project examined the distinct binding partners of the two female-specific DSX isoforms with the specific aims of improving our understanding of insect sex development and discovering new gene targets for female lethality. A subset of 12 genes identified in the mass spectrometry assay were further subjected to RNA interference assays where female-specific developmental impacts were assessed. Data from this project may be applied to improve sex-sorting of mosquitoes in sterile insect technique approaches.