摘要
鱼类脑垂体分泌的促性腺激素(GtHs)与分布在性腺中的促性腺激素受体(GtHRs)所形成的信号通路,在性腺发育过程中发挥了重要作用.为了解GtH/GtHR信号通路在雌性先熟雌雄同体鱼类性腺发育过程中的作用,本文克隆了赤点石斑鱼(Epinephelus akaara)GtHsβ亚基(FSHβ和LHβ)及其受体GtHRs(Fshr和Lhcgr)基因的序列,并分析了它们在性腺发育过程中的表达模式.结果表明:FSHβ和LHβ具有糖蛋白激素家族成员保守的结构特征;Fshr和Lhcgr具有糖蛋白激素受体亚家族保守的结构特征;FSHβ和LHβ基因仅在脑垂体表达,而Fshr和Lhcgr基因仅在性腺表达;在性逆转早期(ET)阶段FSHβ表达量处于低水平,但在性逆转后期(LT)阶段和雄性阶段表达量升高;LHβ的表达模式与FSHβ相似,但从ET阶段到LT阶段,与FSHβ相比其表达量的升高幅度较低;性腺中Fshr和Lhcgr在雌性和ET阶段表达量都很低,LT阶段明显上升,雄性阶段达到最高水平,但Fshr表达量远远高于Lhcgr.研究结果提示,GtH/GtHR通路参与了赤点石斑鱼的性腺发育过程,其中FSH信号通路在这过程中可能发挥更主要的作用.
In teleost,signaling pathways between gonadotropins （GtHs） in pituitary and gonadotropin receptors （GtHRs） in gonad play important roles in gonadal development.To gain insights into the involvement of GtH/GtHR systems in the gonadal development and sex change process, cDNAs encoding GtHs and their receptors were firstly cloned from Epinephelus akaara, a protogynous hermaphrodite fish,and the expression profiles of GtHβ subunits （FSHβ and LHβ） and their receptors （Fshr and Lhcgr） were analyzed.Sequence analyses showed that FSHβ and LHβ were characterized by the glycoprotein hormones family,and Fshr and Lhcgr were characterized by the glycoprotein hormone receptors subfamily in E. akaara.FSHβ and LHβ were only expressed in pituitary, while Fshr and Lhcgr were only expressed in gonad.During the sex change, the expression of FSHβ was low at early transition （ET） stage and increased at late transition （LT） and male （M） stages.The expression pattern of LHβ was similar to that of FSHβ, while from ET to LT stages,compared with FSHβ,LHβ expression levels showed a slower increase.The expression levels of both Fshr and Lhcgr were low from F I to ET stages,increased significantly at LT stage,and reached the highest level at M stage.The expression level of Fshr was much higher than that of Lhcgr.Taken together,our results suggest that GtH/GtHR systems are involved in the process of gonadal development and sex change in E. akaara, among which the signaling pathway of FSH possibly plays more important roles than that of LH.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2016年第1期37-45,共9页
Journal of Xiamen University：Natural Science
基金
国家自然科学基金(41276129)
高等学校博士学科点专项科研基金(20120121110029)
