Abstract
Acetylcholinesterase activity induction by ecdysteroids is known in Drosophila melanogaster Kc cells, but its induction at the gene expression level has not been studied. A reporter plasmid was constructed by ligation of the D. melanogaster acetylcholinesterase gene (Ace gene) 5'-upstream 1.62 kb region to firefly luciferase cDNA. The plasmid was then introduced into Kc cells by the electroporation method for induction study. With the addition of 1.0 × 10-8 M 20-hydroxyecdysone, a 4-fold induction of luciferase was observed 72 h after the hormone treatment, while 1.0 × 10-6 M ecdysone was required to give a 5-fold induction. Dibenzoyl hydrazines (RH 5849 and RH 5992), which are known as non-steroidal ecdysteroid agonists, also induced a 3 to 4-fold induction, whoever, RH 5992 showed a higher induction potential than RH 5849 (as in other ecdysteroid assays). These results suggest that this novel ecdysteroid responsive reporter plasmid (system) might be useful for the evaluation of ecdysteroids and further analysis of the acetylcholinesterase induction mechanism by ecdysteroids.
