Zheng Guo-Dong, Sun Cheng-Fei, Pu Jian-Wei, Chen Jie, Jiang Xia-Yun, Zou Shu-Ming
Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China.
Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China.
Gen Comp Endocrinol. 2015 Apr 1;214:68-76. doi: 10.1016/j.ygcen.2015.03.008. Epub 2015 Mar 26.
Myostatin (MSTN) is an important negative regulator of myogenesis, which inhibits myoblast proliferation and differentiation. Here, we report the isolation and characterization of two mstn genes in grass carp (Ctenopharyngodon idellus). Grass carp mstn-1 and mstn-2 cDNAs are highly divergent, sharing a relatively low amino acid sequence identity of 66%. In adult fish, both orthologs are expressed in numerous tissues and they are differentially regulated during a fasting/refeeding treatments. During embryogenesis, the mRNA levels of both mstn-1 and -2 were upregulated significantly at the beginning of somitogenesis, and maintained at high levels until hatching. Using in situ hybridization, grass carp mstn-1 mRNA was found to ubiquitously express at 12hpf, with strong signals in the notochord, and in the eyes, brain and tailbud at 24hpf, and in brain and notochord at 36hpf. In comparison, the mstn-2 mRNA can be detected in the eyes, brain and notochord at 24hpf, and in the notochord and hindbrain at 36hpf. Further overexpression of mstn-1 mRNA caused a strongly ventralized phenotype by inhibiting dorsal tissue development, while injection of mstn-2 mRNA resulted in obvious embryonic abnormalities in grass carp. These results provide some new insights into the functional conservation and divergence of mstn genes in teleost species.
肌肉生长抑制素（MSTN）是肌肉生成的重要负调控因子，可抑制成肌细胞的增殖和分化。在此，我们报告草鱼（Ctenopharyngodon idellus）中两个mstn基因的分离与特征。草鱼mstn - 1和mstn - 2 cDNA高度不同，氨基酸序列同一性相对较低，为66%。在成年鱼中，两个直系同源基因在许多组织中表达，并且在禁食/再投喂处理期间受到不同的调控。在胚胎发育过程中，mstn - 1和 - 2的mRNA水平在体节发生开始时显著上调，并在孵化前维持在高水平。通过原位杂交发现，草鱼mstn - 1 mRNA在12hpf时普遍表达，在24hpf时在脊索、眼睛、脑和尾芽中有强信号，在36hpf时在脑和脊索中有信号。相比之下，mstn - 2 mRNA在24hpf时可在眼睛、脑和脊索中检测到，在36hpf时在脊索和后脑中有信号。进一步过表达mstn - 1 mRNA通过抑制背侧组织发育导致强烈的腹化表型，而注射mstn - 2 mRNA则导致草鱼胚胎出现明显异常。这些结果为硬骨鱼物种中mstn基因的功能保守性和差异性提供了一些新的见解。
