[Cloning and promoter analysis of gonadotrophin-releasing hormone â ¡ in the orange-spotted grouper (Epinephelus coioides)].

Gonadotrophin-releasing hormone (GnRH) is a key regulator of reproduction in all vertebrates. We first cloned the cDNA and genomic DNA sequences coding for GnRHⅡ gene in the orange-spotted grouper (Epinephelis coioides), an economically important marine fish, and then cloned its promoter sequence. The region responsible for the cell-specific expression of GnRHⅡ was located between -2005 bp to -956 bp from the translation start site. GnRHⅡ promoter driven EGFP expression in transgenic zebrafish showed that GnRHⅡ-positive neurons were primarily located in the midbrain and in the eyes. Our results provide an improved understanding of the regulatory mechanism and function of GnRHⅡ of E. coioides.