Identification and localization of a novel ecdysone oxidase in the silkworm, Bombyx mori

Abstract

Ecdysone oxidase (EO) is an enzyme that catalyzes the oxidation of ecdysteroids, the molting steroid hormones in insects. This enzyme may play important roles in the conversion of ecdysteroids to 3-dehydroecdysteroids. In this study, we identified a novel EO, designated bmEO2, from the silkworm, Bombyx mori. A cDNA encoding bmEO2 was cloned by employing the reverse transcriptase-polymerase chain reaction (PCR) technique. The deduced amino acid sequence of bmEO2 showed conserved residues and sequence homology to other known insect EOs and glucose dehydrogenase proteins. Quantitative real-time PCR revealed that the bmEO2 transcript was abundantly present in larval testes of B. mori.