Regulation of the ecdysone receptor, USP, E75 and MHR3 mRNAs by 20-hydroxyecdysone in the GV1 cell line of the tobacco hornworm, Manduca sexta.

摘要

The responsiveness of several nuclear transcription factor genes to 20-hydroxyecdysone [ecdysterone] was characterized in an embryonic cell line, GV1, from Manduca sexta. The messenger RNA for the Manduca ecdysone receptor (MsEcR) was present in theGV1 cells and transiently increased 2.3-fold by 5 h after the addition of 2 鎔/ml (4 X 10-6 M) ecdysterone. In contrast, Manduca ultraspiracle (MsUSP) messenger RNA concn in the GV1 cells decreased slowly to half of its initial concn by 12 h when exposed to the same concn of ecdysterone. The messenger RNAs for 2 putative transcription factors, MsE75 and MHR3, were induced in the GV1 cells by ecdysterone, with that for E75 appearing within 1 h, whereas that for MHR3 appeared within 2 h. The ED50s for the induction of MsE75 and MHR3 gene expression in GV1 cells were 1.2 and 2.5 X 10-6 M ecdysterone, resp.