Genomic Characterization and Expression of Juvenile Hormone Esterase-Like Carboxylesterase Genes in Pacific White Shrimp Litopenaeus vannamei

摘要

The sesquiterpenoid methyl farnesoate (MF), a juvenile hormone (JH) analog, plays important roles in many physiological processes of crustaceans, such as morphogenesis, molting and reproduction. Juvenile hormone esterase-like (JHE-like) carboxylesterase (CXE) is a key enzyme in MF degradation, playing a significant role in regulating MF titer. However, its function is barely known in shrimp. In this study, a total of 21 JHE-like CXEs ( s) were characterized in Pacific white shrimp , based on the full genome and multi-transcriptomic data. has a conserved triplet catalytic site (Ser-Glu-His) and a characteristic GxSxG motif. Most s were highly expressed in the hepatopancreas, which was the main site for MF degradation. s containing a GESAG motif showed a specific expansion in the genome. Those GESAG-containing s presented differential expressions at different larvae stages and different molting stages of , which suggested their potential functions in development and molting. Additionally, when the transcription level of CXEs was inhibited, it could lead to failed molt and death of . When we further detected the expression levels of the key ecdysone responsive transcription factors including , , and after the CXE inhibitor was injected into , they all showed apparent down-regulation. These results suggested that the expansion of s in the genome should contribute to the regulation of metamorphosis at larvae stages and frequent molting during the growth of .