The molecular regulation of Chinook salmon gonadotropin β-subunit gene transcription

Expression of the gonadotropin β-subunit genes is tightly regulated both cell-specifically and by the regulatory hormones to achieve the appropriate gonadotropic hormone levels required for reproductive development and function. Although the cDNA sequences of these genes are highly conserved across species, their promoter sequences are not and few functional studies have been carried out to understand the molecular mechanisms through which their expression is regulated. We and others have carried out several studies on the LHβ gene promoter of Chinook salmon (Oncorhynchus tschawytscha), and also isolated the FSHβ gene from the same species. We present here a review of these studies and also novel data pertaining to both genes, in an attempt to collate the current understanding of the molecular regulation of the gonadotropin β-subunit genes in these fish.