珍珠鸟和家鸡甲状旁腺激素3型受体(PTH3R)的结构与表达图谱分析

Cloning and Functional Analysis of a Novel Splice Variant of Follicle-Stimulating Hormone Receptor (FSHR) in Chickens

摘要:

卵泡刺激素受体（FSHR）主要表达于性腺组织中，可介导卵泡刺激素（FSH）对脊椎动物性腺发育与功能的调控作用。本研究以家鸡为材料，利用RT-PCR技术，从家鸡卵巢中克隆了卵泡刺激素受体的一种新型剪接变体（cFSHR-v）。基因结构与氨基酸序列比对分析表明，该剪接变体在8号外显子的5’端发生了差别剪切，导致了其相比于正常形式FSHR多出21个核苷酸，由此推测该变体（cFSHR-v）可以编码含有700个氨基酸残基的受体蛋白。与正常形式cFSHR相比较，cFSHR-v在N端胞外域增加了7个氨基酸残基。采用RT-PCR技术和pGL3-CRE荧光素酶报告系统，本研究也探究了cFSHR-v的功能及其在家鸡组织中的表达情况。结果显示，FSHR在家鸡卵巢及精巢组织中均有较高表达水平，但在CHO细胞中表达的cFSHR-v不能有效介导卵泡刺激素（FSH）对下游cAMP-PKA信号通路的刺激效应。以上研究结果显示：在家鸡性腺中，FSHR存在剪切变体形式，但其生理功能仍待深入探究。

Abstract:

Follicle-stimulating hormone (FSH) receptor is mainly expressed in gonadal tissues and plays significant roles in mediating the actions of FSH in gonadal development and functions in vertebrates. In this study, a novel splice variant of FSHR (cFSHR-v) was identified from chicken ovary by RT-PCR. cFSHR-v is predicted to encode a putative protein of 700 amino acids with an alternated extracellular domain. Comparison of this splice variant with chicken genome database revealed that it is resulted from partial sequence (21bp) retention of intron 7. RT-PCR assay showed that cFSHR-v could be detected in ovary and testis. Using a pGL3-CRE-Luciferase reporting system, we demonstrated that only cFSHR, but not cFSHR-v, expressed in cultured CHO cells could be activated by human FSH in a dose-dependent manner, indicating that cFSHR-v may be incapable of transmitting signal. Our data revealed that FSHR variant is expressed in chicken gonads, however, its physiological remains to be elucidated.