Elongases of Long-Chain Fatty Acids ELO2 and ELO9 Are Involved in Cuticle Formation and Function in Fecundity in the Yellow Fever Mosquito, .

Long-chain fatty acid elongases (ELOs) play important roles in the metabolism of fatty acids in insects. In this study, the genes for two elongases from were identified, and . Quantitative real time PCR showed that and are expressed at all developmental stages and some body parts, but with different expression patterns. RNAi-mediated knockdown of and was performed to investigate their roles in the development, growth, osmotic balance, and cold tolerance of . Knockdown of slowed larval growth and development by causing molting abnormalities. Additionally, 33% ± 3.3% of adults died during oviposition, accompanied by an abnormal extension of cuticles in -dsRNA knockdown mosquitos. Knockdown of resulted in abnormal balance of cuticular osmotic pressure and a reduction in egg production. The maximal mRNAs of and were detected in eggs at 72 h after oviposition. Moreover, knockdown reduced the egg hatching rates and knockdown larvae did not develop well. In summary, is involved in larval molting and growth, and its knockdown affects the flexibility and elasticity of adult mosquito cuticles. regulates cold tolerance, osmotic balance, and egg development in .