Song Feibiao, Wang Lanmei, Zhu Wenbin, Fu Jianjun, Dong Juanjuan, Dong Zaijie
Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, Jiangsu, China.
Freshwater Fisheries Research Centre of Chinese Academy of Fishery Sciences, Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Wuxi, Jiangsu, China.
PLoS One. 2016 Dec 21;11(12):e0168874. doi: 10.1371/journal.pone.0168874. eCollection 2016.
Since the insulin-like growth factor 3 (igf3) gene was recently discovered in fish ovary, its function in the gonads has received much attention. In this study, we isolated two igf3 subtypes from common carp (Cyprinus carpio), which comprised full-length cDNA of 707 and 1153 nucleotides encoding 205 and 198 amino acids (aa), respectively. The Igf3 aa sequence had the highest gene homology of 72% with the corresponding sequence in zebrafish (Danio rerio). Phylogenetic tree construction revealed that the C. carpio igf3 gene was first clustered with D. rerio and then with other teleost species. Igf3 mRNA was widely expressed, with expression being highest in the gonads and blood. In the gonad development stage, igf3a mRNA expression was highest in the maturity and recession stage of the ovary, and decline phase of the testis, while igf3b was highest in the recession and fully mature periods of the ovaries and testes, respectively. Western blotting of testis protein samples showed two bands of approximately 21 kDa and 34 kDa corresponding to the calculated molecular mass of the two Igf3 subtypes; no signal was detected in the ovary. The Igf3 protein was localized in the ovary granulosa cells and testis spermatogonium and spermatids. 17β-Ethinylestradiol treatment increased both ovary and testis igf3 mRNA expression. These findings suggest that Igf3 may play an important role in C. carpio gonadal development.
自从胰岛素样生长因子3（igf3）基因最近在鱼类卵巢中被发现以来，其在性腺中的功能备受关注。在本研究中，我们从鲤鱼（Cyprinus carpio）中分离出两种igf3亚型，其全长cDNA分别为707和1153个核苷酸，分别编码205和198个氨基酸（aa）。Igf3氨基酸序列与斑马鱼（Danio rerio）中的相应序列具有72%的最高基因同源性。系统发育树构建显示，鲤鱼igf3基因首先与斑马鱼聚类，然后与其他硬骨鱼物种聚类。Igf3 mRNA广泛表达，在性腺和血液中的表达最高。在性腺发育阶段，igf3a mRNA表达在卵巢的成熟和衰退阶段以及睾丸的衰退期最高，而igf3b分别在卵巢和睾丸的衰退期和完全成熟期最高。睾丸蛋白质样品的蛋白质印迹显示出两条约21 kDa和34 kDa的条带，对应于两种Igf3亚型的计算分子量；在卵巢中未检测到信号。Igf3蛋白定位于卵巢颗粒细胞以及睾丸精原细胞和精子细胞中。17β-炔雌醇处理增加了卵巢和睾丸igf3 mRNA的表达。这些发现表明Igf3可能在鲤鱼性腺发育中发挥重要作用。
