Elucidating the Regulatory Mechanism of the Transcription Factor Krüppel homolog 1 in Mosquito Reproduction

Abstract

Insect juvenile hormone (JH) plays a crucial role during reproduction in adult mosquitoes. Krüppel homolog 1 (Kr‐h1) is a transcription factor that is upregulated by JH. However, the molecular action of AaKr‐h1 in the JH‐regulated gene expression has not yet been well studied in adult mosquitoes. Our recent ChIP‐seq study has indicated that Kr‐h1 in Aedes aegypti binds to the promoter regions of genes that are under the control of JH or another crucial insect hormone, 20‐hydroxyecdysone (20E). Therefore, we hypothesize that AaKr‐h1 modulates the JH and 20E responses in adult mosquitoes. We have performed RNAi mediated gene silencing to examine the regulatory function of AaKr‐h1 on the selected JH (Met, Early Trypsin) and 20E (EcRA, HR3, E75A, βFTZ‐F1, and E93) responsive genes. Successful knockdown at the mRNA and protein levels was confirmed by Quantitative PCR (qPCR) and Western blot analyses respectively. In the AaKr‐h1 depleted mosquitoes, most of the selected JH and 20E responsive genes showed considerable alteration in their expression. Knockdown of AaKr‐h1 led to an increase in the expression of Early Trypsin and a significant reduction in the expression of Met, EcRA, HR3, and E93. In conclusion, our study showed that AaKr‐h1 regulates the expression of diverse genes that are crucial for egg maturation in adult female mosquitoes. Ae. aegypti is a vector of several tropical diseases including yellow fever, dengue, chikungunya and zika fever. The growing resistance to many of the currently used insecticides in mosquitoes creates an urgent need to develop novel insecticides with unique modes of action. This study will advance our understanding of the regulatory mechanism of AaKr‐h1 during reproduction and might provide a new target for novel insecticides to suppress mosquito population.Support or Funding InformationNIHThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.