Role of arylalkylamine N‐acetyltransferase 7 in reproduction and limb pigmentation of Aedes aegypti

Abstract

AbstractArylalkylamine N‐acetyltransferase (aaNAT) is a crucial enzyme that catalyses the transfer of acetyl groups from acetyl coenzyme A to arylalkylamines and arylamines. Evolutionary studies have identified a distinct class of aaNATs specific to mosquitoes, yet their functions remain elusive. This study focuses on Ae‐aaNAT7, a mosquito‐unique gene in Aedes aegypti (Diptera:Culicidae), to explore its functionality. Temporal and spatial expression analysis of Ae‐aaNAT7 mRNA revealed high expression during embryonic development and in first‐instar larvae, with notable expression in the limbs of adult mosquitoes based on tissue expression profiling. By further employing CRISPR/Cas9 technology for loss‐of‐function studies, our investigation revealed a reduction in the area of white spotting in the limbs of Ae‐aaNAT7 mutant adult mosquitoes. Further investigation revealed a significant decrease in the fecundity and hatchability of the mutants. Dissection of the ovaries from Ae‐aaNAT7 heterozygous mutants showed a noticeable reduction in the oocyte area compared with wild type. Dissection of the exochorion of the eggs from Ae‐aaNAT7 homozygous mutants consistently revealed a striking absence of mature embryos. In addition, RNA interference experiments targeting Ae‐aaNAT7 in males resulted in a reduction in fecundity, but no effect on hatchability was observed. These collective insights underscore the substantial impact of Ae‐aaNAT7 on reproduction and its pivotal contribution to adult limb pigmentation in Ae. aegypti. These revelations offer insights pivotal for the strategic design of future insecticide targets.