Dan Cheng, Lin Qiaohong, Gong Gaorui, Yang Tianyi, Xiong Shuting, Xiong Yang, Huang Peipei, Gui Jian-Fang, Mei Jie
College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Wuhan 430072, China.
Sci Bull (Beijing). 2018 Nov 15;63(21):1420-1430. doi: 10.1016/j.scib.2018.08.012. Epub 2018 Aug 31.
The sex-determining genes are found to be variable among different fish species. Yellow catfish (Pelteobagrus fulvidraco) is an important aquaculture fish species in China with XX/XY sex-determining type. Recently, YY super-male yellow catfish has been successfully produced by combining hormonal-induced sex reversal method with sex chromosome-linked markers. Here, we identified a novel PDZ domain-containing gene in yellow catfish designated as pfpdz1, in whose intron the sex-linked marker was located. The coding sequence of pfpdz1 in Y chromosome was identical to that in X chromosome except a missense SNP (A/T) that changes an amino acid (E8V) in the N-terminal region. Pfpdz1 displayed male-specific expression during sex differentiation. Overexpression of pfpdz1 using additive transgenesis induces XX ovary to differentiate into testis-like tissue, while the targeted inactivation of pfpdz1 in Y chromosome using CRISPR/Cas9-mediated mutagenesis triggers ovarian differentiation. Furthermore, we demonstrated that pfpdz1 initiates testicular differentiation through upregulating expression of amh, dmrt1 and sox9a1, as well as downregulating expression of cyp19a1, foxl2 and wnt4. Our data provide functional evidence that pfpdz1 is significant for male differentiation and maintenance in yellow catfish.
研究发现，性别决定基因在不同鱼类物种中存在差异。黄颡鱼（Pelteobagrus fulvidraco）是中国重要的水产养殖鱼类，具有XX/XY性别决定类型。最近，通过将激素诱导性逆转方法与性染色体连锁标记相结合，成功培育出了YY超雄黄颡鱼。在此，我们在黄颡鱼中鉴定出一个新的含PDZ结构域的基因，命名为pfpdz1，其内含子中存在性连锁标记。Y染色体上pfpdz1的编码序列与X染色体上的编码序列相同，只是存在一个错义单核苷酸多态性（A/T），该多态性导致N端区域的一个氨基酸发生改变（E8V）。Pfpdz1在性别分化过程中表现出雄性特异性表达。通过添加转基因技术过表达pfpdz1可诱导XX卵巢分化为睾丸样组织，而利用CRISPR/Cas9介导的诱变技术靶向失活Y染色体上的pfpdz1则会引发卵巢分化。此外，我们证明pfpdz1通过上调amh、dmrt1和sox9a1的表达以及下调cyp19a1、foxl2和wnt4的表达来启动睾丸分化。我们的数据提供了功能证据，表明pfpdz1对黄颡鱼的雄性分化和维持具有重要意义。
