Isolation, cloning and characterization of the FSH-beta gene promoter of the chinook salmon (Oncorhynchus tshawytscha)

Abstract

The follicle stimulating hormone (FSH) plays a crucial role in reproductive activity. However little is understood about the mechanisms regulating its transcription. The aim of this research was to initiate a study on the molecular mechanisms regulating transcription of the FSH I? subunit gene of the Chinook salmon. The 1.2 kb promoter of FSH was unable to activate transcription of a reporter gene alone, but was responsive to over-expression of SF-1, c-jun or Smad1. Interestingly, a 1 kb fragment (intronic enhancer) within the first intron was not only able to drive expression of a reporter gene, but was also responsive to GnRH and activin. The effect of over-expression of a number of transcription factors (e.g. SF-1, Smad1, c-jun and liganded estrogen receptor ER) was also tested, and were found to stimulate powerfully transcription by this fragment.