Characterization of juvenile hormone epoxide hydrolase and related genes in the larval development of the silkworm Bombyx mori.

Juvenile hormone epoxide hydrolases (JHEHs) are a family of enzymes that hydrolyze juvenile hormones (JHs). They are important in terms of organ-specific regulation and irreversible degradation. In contrast to three JHEH genes (jheh) in Drosophila melanogaster and five jheh in Tribolium castaneum, only one jheh gene has been reported to date in lepidopteran insects.

Molecular characterization and functional analysis of novel carboxyl/cholinesterases with GQSAG motif in the silkworm Bombyx mori.

We have previously cloned and characterized BmJHE, a juvenile hormone (JH)-selective esterase (JHE) that is important for JH titer regulation in the silkworm Bombyx mori. Here, we sought to determine whether multiple genes might function as JH-specific esterase in this species. We searched for putative carboxyl/cholinesterase (CCE) genes having GQSAG, a highly conserved motif in JHE, by the use of silkworm genomic database.

Molecular cloning and expression analysis of ultraspiracle (USP) from the rice stem borer Chilo suppressalis.

cDNA for ultraspiracle (USP) from the lepidopteran rice stem borer Chilo suppressalis was cloned using PCR techniques. The deduced amino acid sequence of C. suppressalis USP (CsUSP) was very similar to those of other lepidopteran USPs, especially to the Manduca sexta USP-2 isoform.

A possible role of 20-hydroxyecdysone in embryonic development of the silkworm Bombyx mori.

It has been well established that eggs of insects, including those of the silkworm Bombyx mori, contain various ecdysteroids and the amounts of these ecdysteroids fluctuate during embryonic development. In order to know the function of egg ecdysteroids in embryonic development of B. mori, we examined the biological activities of various egg ecdysteroids by in vitro ligand-binding assay and bioassay using B.