The effect of targeted silencing of ferritin in the yellow fever mosquito, Aedes aegypti

Abstract

Mosquitoes are vectors of human pathogens that cause disease, such as malaria, yellow fever and dengue fever. Pathogen transmission occurs when the female mosquito takes a bloodmeal from a human host. The female mosquito must bloodfeed for egg production, or oogenesis. An essential and concentrated nutrient in the blood meal is iron, which is required for optimal egg development and viable offspring. Ferritin is a major iron‐storage and transport protein expressed in mosquitoes. The protein increases following a blood meal in the female ovaries, midgut, fat body and hemolymph. Insect ferritin consists of 24 subunits of the heavy chain homologue (HCH), which contains the site for ferroxidase activity, and the light chain homologue (LCH), which is used for iron storage. This study evaluates the importance of these subunits for iron transport and storage within mosquitoes by suppressing them using RNA interference (RNAi) techniques. We suppressed ferritin expression by injecting the animals with double stranded RNA (dsRNA) and collecting whole animals, their tissues and eggs following blood feeding to examine the effect of message knockdown and protein expression. Interfering with iron delivery and usage in mosquitoes may be a strategy to reduce the number of eggs laid and pathogen transmission rates. Research support from NIH (GM056812), the Undergraduate Biology Research Program and a grant from the Honors College from the University of Arizona.