许氏平鲉三种促性腺激素释放激素基因的启动子克隆及生物信息学分析

促性腺激素释放激素(GnRH)是1种在下丘脑-垂体-性腺轴(Hypothalamus-pituitary-gonad,HPG)的活动中发挥关键作用的神经激素。研究采用染色体步移方法,从许氏平鲉的肌肉组织中克隆得到GnRH1、GnRH2和GnRH3共3个基因的启动子序列,长度分别为4,3.5和2.5kb。利用在线生物信息学软件对这3个GnRH基因的启动子进行预测分析,结果表明,3个基因均存在Sp1,Oct-1,C/EBP,CREB,Pit-1,NF-1,Brn,GATA-1,USF和MyoD等转录因子的结合位点,以及糖皮质激素受体(GR),雄激素受体(AR),雌激素受体(ER),黄体酮受体(PR),视黄酸受体(RAR)和视黄醇受体(RXR)等核受体的结合位点,推测其对GnRH的调控起到关键作用。但是甲状腺激素受体(TR)和嗅觉相关的Olf-1的结合位点只在GnRH1和GnRH2基因启动子中发现,而在GnRH3中没有预测出。本研究结果表明许氏平鮋不同类型的GnRH是受不同的机制调控的,从而在生理过程中发挥着不同的作用。

Cloning and Bioinformati Analysis of the Promoters from Three Gonadotropin-Releasing Hormone Genes of Sebastes schlegelii

Gonadotropin-releasing hormone(GnRH),a neuropeptide,plays a vital role in the functioning of hypothalamus-pituitary-gonad(HPG) axis.In this study,the promoters of GnRH1,GnRH2 and GnRH3 genes of black rock fish(Sebastes schlegelii) were cloned by genome walking.The promoters of these 3 genes were 4,3.5 and 2.5 kb in length,respectively.Using on line bioinformatic analysis softwares,we found each promoter contained putative binding sites for Sp1,Oct-1,C/EBP,CREB,Pit-1,NF-1,Brn,GATA-1,USF and MyoD.Three promoters also contained the binding sites of nuclear receptors including glucocorticoid receptor(GR),androgen receptor(AR),estrogen receptor(ER),progesterone receptor(PR),retinoic acid(RAR) and retinoid X receptors(RXR).These binding sites should play similar roles in GnRH regulation;they were conservative among three promoters.Three promoters should function differentially;binding sites for thyroid hormone receptor(TR) and Olf-1 existed in the promoters of GnRH1 and GnRH2 but not in promoter of GnRH3.