UC Riverside

Female mosquitoes require a blood meal for reproduction, providing the underlying mechanism for the spread of many devastating parasitic and viral vector-borne diseases in humans. A deeper understanding of the molecular mechanisms linked to mosquito blood meal processes, reproductive events and anti-pathogen immunity is of particular importance for devising innovative vector control strategies. Acquisition of blood initiates a cascade of events – including dynamic changes in microRNA (miRNAs) expression – in various tissues in the female mosquito. miRNAs are a class of endogenous regulatory RNA molecules 21-24 nucleotides in length that modulate gene expression at the post-transcriptional level via base pairing to target sites within messenger RNAs (mRNA). Reports have indicated that miRNAs are differentially expressed in various tissues of the female mosquito upon the uptake of a blood meal. miRNAs have been shown to play important roles in regulation gene expression throughout the adult mosquitoes life cycle – including the regulation of adult development, blood digestion and mosquito-pathogen interaction. Furthermore, several lineage-specific miRNAs have been identified in mosquitoes and may underlie mosquito-specific events, including blood meal-initiated events. This thesis describes the fat body specific function of the conserved miRNA, miR-8, in the female mosquito post-blood meal and its involvement in regulating essential reproductive events through targeting the Wingless signaling pathway. Additionally, this thesis details the function of two lineage-specific miRNAs, miR-1174 and miR-1890, and their involvement in regulating digestive processes in the female mosquito midgut. Together, these studies have established a fundamental role for both conserved and lineage-specific miRNAs in the adult female mosquito.