Abstract
Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was used to study developmental expression and hormonal regulation of the juvenile hormone esterase gene (DmJhe) in the fruit fly, Drosophila melanogaster. The levels of DmJhe mRNA were low during the embryonic stage. A peak of Dmjhe mRNA was detected in the first, second and third instar larvae. The Dmjhe mRNA levels also increased soon after pupal ecdysis. The Dmjhe mRNA was detected in both male and female adult flies. The peaks of Dmjhe mRNA observed in the larvae coincided with the peaks of juvenile hormone (JH). In contrast, the mRNA for ecdysone-induced transcription factor, Drosophila hormone receptor 3 (DHR3) showed peaks of expression that coincided with the ecdysteroid peaks in embryo, larva and pupa. JH III induced Dmjhe mRNA but not DHR3 mRNA in explanted tissues cultured in Grace's medium. 20-hydroxyecdysone induced DHR3 mRNA and suppressed JH III induction of DmJhe mRNA. These studies show that the expression of jhe in D. melanogaster is regulated by both JH and 20E.
