Cloning and functional analysis of the proximal promoter region of the three GnRH genes from the silver sea bream (Sparus sarba).
Gonadotropin-releasing hormone (GnRH) is a neuropeptide that plays a major role in releasing pituitary gonadotropin and controlling vertebrate reproduction. In this study, three GnRH cDNAs, GnRH-I (sbGnRH; 348 bp), GnRH-II (cGnRH-II; 557 bp), and GnRH-III (sGnRH; 483 bp), were cloned from the brain of the silver sea bream (Sparus sarba). In order to understand how the expression of the GnRH isoforms was regulated in the brain, the promoter of each gene was cloned and analyzed. We found regulatory motifs in the promoters that were conserved in the GnRH promoters of tilapia and zebrafish, suggesting that these motifs play a critical role in GnRH regulation. We performed functional analyses and examined tissue-specific expression for each GnRH promoter using EGFP reporter fusions in zebrafish. The GnRH-I promoter was active in the forebrain area, including the olfactory bulb-terminal nerve area and peripheral preoptic areas; the GnRH-II promoter was active in the midbrain; and the GnRH-III promoter was active in the olfactory bulb. These results show that the GnRH promoters of the silver sea bream GnRH genes exhibit tissue-specific activity.
Hu
Shao-Yang
SY
Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, Taiwan.
Chen
Mark Hung-Chih
MH
Lin
Yi-Chia
YC
Lin
Gen-Hwa
GH
Gong
Hong-Yi
HY
Yang
Tzu-Hsuan
TH
Wu
Jen-Leih
JL
D000818:Animals; D001923:Brain Chemistry; D003001:Cloning, Molecular; D017124:Conserved Sequence; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics*; D008636:Mesencephalon; D009830:Olfactory Bulb; D011301:Preoptic Area; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016548:Prosencephalon; D020033:Protein Isoforms; D021541:Sea Bream
D020033:Protein Isoforms; D007987:Gonadotropin-Releasing Hormone