Isolation and expression of the ecdysteroid-inducible angiotensin-converting enzyme-related gene in wing discs of Bombyx mori

We isolated a clone encoding a putative angiotensin-converting enzyme-related gene from the wing disc cDNA library of the silkworm, Bombyx mori (refer to as BmAcer). The predicted open reading frame encoded 648 amino acids with about 50% identities with the Drosophila melanogaster angiotensin-converting enzyme Ance and Acer. Northern analysis identified a 2.2-kilobase mRNA which was abundant in wing discs two days after the beginning of wandering. An accumulation of the transcript was observed approximately 2 h after 20–hydroxyecdysone (20E) exposure in vitro and was blocked slightly by a protein synthetic inhibitor. These data suggest that the transcription of the BmAcer gene is directly 20E-inducible.