Molecular cloning and functional analysis of the zebrafish follicle-stimulating hormone (FSH)β promoter

In the present study, we cloned and characterized a zebrafish follicle-stimulating hormone (zfFSH)β promoter with deletion fragments transfected into a tilapia ovary (TO2) cell line, and demonstrated that the zfFSHβ promoter responded to 6 h of gonadotropin-releasing hormone (GnRH) treatment by activating calcium influx and protein kinase C (PKC), but after 24 h, GnRH induction was generated by activation of extracellular-regulated kinase (ERK)1/2 and repression by PKC. Furthermore, to study the promoter-specific expression, we constructed a series of FSHβ (4.0-, 3.0-, 2.0-, and 1.0-kb) promoter-driven green fluorescent protein (GFP) fragments encoding the GFP complementary DNA transgene which was microinjected into zebrafish embryos. Morphological studies of transgenic zebrafish indicated that the FSHβ promoter-driven GFP transcripts appeared in the heart, skin, and vertebrae.