Jiang Yonghua, Han Kunhuang, Chen Shihai, Cai Mingyi, Wang Yilei, Zhang Ziping
Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture; Fisheries College, Jimei University, Xiamen, 361021, China; State Key Laboratory of Large Yellow Croaker Breeding, Ningde Fufa Fisheries Company Limited, Ningde, 352103, China.
Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture; Fisheries College, Jimei University, Xiamen, 361021, China.
Gene Expr Patterns. 2018 Jan;27:16-30. doi: 10.1016/j.gep.2017.10.001. Epub 2017 Oct 4.
Octamer-binding transcription factor 4 (Oct4) is a crucial pluripotent transcription factor in controlling pluripotency of embryonic stem cells (ESCs), formation of primordial germ cells (PGCs), early embryonic development, and gonadal germ cells. To understand the roles of Oct4 in the large yellow croaker (Larimichthys crocea) (Lc-Oct4), the full-length cDNA of Oct4 was cloned and analyzed. Lc-Oct4 includes a 104-bp 5' untranslated region (UTR), a 567-bp 3' UTR and a 1431-bp coding region encoding a protein of 476 amino acids (aa) with a predicted molecular mass (Mm) of 52.40 kDa and an isoelectric point (PI) of 6.34. Quantitative real time PCR (qRT-PCR) in tissues showed that Lc-Oct4 was only expressed in ovary. During ovarian development, the expression level in 635 days post hatching (635-dph) ovary was about 6.3-fold higher than in 270-dph and 1000-dph ovary. The in situ hybridization analysis showed that Lc-Oct4 had a high expression in the different developmental stages of oocytes with the highest level in stages II (later) and III oocytes. Lc-Oct4 was also expressed in spermatogonia and primary spermatocytes. Furthermore, the qRT-PCR analysis of Lc-Oct4 in different developmental embryos revealed that the expression from high to low was multiple-cell stage > mid-blastula stage = mid-gastrula stage, and the expression in multiple-cell stage was at less 1.6-fold higher than in other stages. Accordingly, the whole mount in situ hybridization (WISH) in embryos demonstrated that Lc-Oct4 was expressed only in early embryonic development from 2-cell stage to early-gastrula stage with the peak at 16-cell stage, but not detected in PGCs area. In conclusion, Lc-Oct4 participated in the oogenesis and early embryonic development in large yellow croaker. Overall, this study provided better understanding of Lc-Oct4 gene and lay the foundation for its function research in the large yellow croaker.
八聚体结合转录因子4（Oct4）是一种关键的多能转录因子，在控制胚胎干细胞（ESC）的多能性、原始生殖细胞（PGC）的形成、早期胚胎发育以及性腺生殖细胞方面发挥着重要作用。为了解Oct4在大黄鱼（Larimichthys crocea）（Lc - Oct4）中的作用，我们克隆并分析了Oct4的全长cDNA。Lc - Oct4包含一个104个碱基对的5'非翻译区（UTR）、一个567个碱基对的3'UTR和一个1431个碱基对的编码区，编码一个由476个氨基酸（aa）组成的蛋白质，预测分子量（Mm）为52.40 kDa，等电点（PI）为6.34。组织中的定量实时PCR（qRT - PCR）结果显示，Lc - Oct4仅在卵巢中表达。在卵巢发育过程中，孵化后635天（635 - dph）卵巢中的表达水平比270 - dph和1000 - dph卵巢中的表达水平高约6.3倍。原位杂交分析表明，Lc - Oct4在卵母细胞的不同发育阶段均有高表达，在II期（后期）和III期卵母细胞中表达水平最高。Lc - Oct4在精原细胞和初级精母细胞中也有表达。此外，对不同发育阶段胚胎中Lc - Oct4的qRT - PCR分析显示，表达量从高到低依次为多细胞期>囊胚中期=原肠胚中期，多细胞期的表达量比其他阶段至少高1.6倍。因此，胚胎的整体原位杂交（WISH）表明，Lc - Oct4仅在从2细胞期到原肠胚早期的早期胚胎发育过程中表达，在16细胞期达到峰值，但在PGC区域未检测到。总之，Lc - Oct4参与了大黄鱼的卵子发生和早期胚胎发育。总体而言，本研究增进了对Lc - Oct4基因的了解，为其在大黄鱼中的功能研究奠定了基础。
