Molecular differences resulting from larval growth conditions in Aedes aegypti

Many aspects of adult mosquitoes which play a role in determining their vectorial and reproductive capacity are heavily influenced by the conditions the mosquito encounters as a larva. Under less than ideal larval crowding and nutritional conditions, the resulting mosquitoes emerge smaller after a longer developmental period. Observations of these smaller mosquitoes has shown less obvious physiological changes, such as they frequently require a second blood meal to produce eggs. The size difference has also been shown to have an impact on vectorial capacity, though the affect has not been fully elucidated and may vary depending on the disease in question. We are working on a transcriptional, metabolomic and metabolic approach to identify molecular differences between mosquitoes raised under standard laboratory conditions versus overcrowded and nutritionally challenged mosquitoes. Through metabolomic analysis, we have identified putative nutritional markers for starvation and overcrowding. We have also identified indications of autophagy. We have not identified differences in metabolic rates between "small" and "large" mosquitoes. Preliminary RNA-seq of the fat body on pre and post blood meal mosquitoes, has identified a number of transcriptional changes which occur post blood meal. We are currently conducting further RNA-seq on the fat bodies of small and large mosquitoes, pre and post-blood meal and have vectorial capacity assays planned. In conclusion, important transcriptional and metabolomic differences exist between mosquitoes raised under high- and low-nutrient and population density regimens. Many of these differences originate in the fat body and may be important in mosquito reproduction, energy homeostasis and immunity.