Inhibin and Activin, belong to the transforming growth factor β superfamily (TGF-β), which associate with the regulation of the reproductive process by the modulation of the hypothalamic-pituitary-gonad (HPG) axis. In this study, we reported the molecular cloning and tissue expression of inhibin α in allotriploid crucian carp and its parent- diploid red crucian carp. The full-length cDNA of inhibin α were respectively 1632 bp and 1642 bp in allotriploids and diploids, which both consisted of a 1044 bp open reading frame (ORF) encoding 347 amino acids. Real-time quantitative PCR (RT-qPCR) showed that allotriploids and diploids had significant expression of inhibin α in testis and ovary, and the expression of inhibin α in the gonads of allotriploids was higher than that of diploids. The immunohistochemistry indicated that the ovarian development of allotriploids was abnormal, and the expression of Inhibin α in the ovary of allotriploids was higher than that of diploids. Results of co-immunoprecitation (co-IP) demonstrated that the Inhibin α and Activin β_A, Inhibin α and Activin β_B can form dimers. These findings suggested that the elevated expression of inhibin α and the competitive binding of Inhibin α subunit with Activin β subunits in allotriploids may be releted to the sterility of allotriploids. Furthermore, these results will facilitate the investigation of reproduction characteristics in allotriploids and provide theoretical basis for the study of polyploid breeding in the future.

抑制素和激活素属于转化生长因子 β 超家族 (TGF-β)，它们通过调节下丘脑-垂体-性腺 (HPG) 轴来调节生殖过程。在本研究中，我们报道了抑制素α在异源三倍体鲫鱼及其亲本二倍体红鲫体内的分子克隆和组织表达。抑制素α的全长cDNA在异源三倍体和二倍体中分别为1632 bp和1642 bp，均由编码347个氨基酸的1044 bp开放阅读框(ORF)组成。实时定量 PCR (RT-qPCR) 显示异源三倍体和二倍体在睾丸和卵巢中显着表达抑制素 α ，抑制素 α表达在异源三倍体的性腺中高于二倍体。免疫组化显示异源三倍体卵巢发育异常，异源三倍体卵巢中抑制素α的表达高于二倍体。共免疫沉淀（co-IP）的结果表明抑制素α和激活素βA _、抑制素α和激活素βB_可以形成二聚体。这些发现表明抑制素α的表达升高异源三倍体中抑制素α亚基与激活素β亚基竞争性结合可能与异源三倍体不育有关。此外，这些结果将有助于研究异源三倍体的繁殖特性，并为未来的多倍体育种研究提供理论依据。