Aquaculture Genetics Research Program, School of Marine and Tropical Biology, James Cook University, Townsville, 4811, Queensland, Australia.
Mol Cell Endocrinol. 2011 Mar 30;335(2):158-65. doi: 10.1016/j.mce.2011.01.011. Epub 2011 Jan 15.
Gene or genome duplication is a fundamental evolutionary mechanism leading towards the origin of new genes, or gene functions. Myostatin (MSTN) is a negative regulator of muscle growth that in teleost fish, as a result of genome duplication, is present in double copy. This study provides evidence of differentiation of MSTN paralogs in fish by comparatively exploring their tissue-regulation in the Asian sea bass (Lates calcarifer) when subjected to fasting stress. Results showed differential regulation as well as specific tissue-responses in the muscle, liver, gill and brain of L. calcarifer after nutritional deprivation. In particular, the LcMstn-1 expression increased in liver (∼4 fold) and muscle (∼3 fold) and diminished in brain (∼0.5 fold) and gill (∼0.5 fold) while that of LcMstn-2 remained stable in brain and muscle and was up regulated in gill (∼2.5 fold) and liver (∼2 fold). Differential regulation of Mstn paralogs was supported by in silico analyses of regulatory motifs that revealed, at least in the immediate region upstream the genes, a differentiation between Mstn-1 and Mstn-2. The Mstn-1 in particular showed a significantly higher conservation of regulatory sites among teleost species compared to its paralog indicating that this gene might have a highly conserved function in the taxon.
基因或基因组复制是一种基本的进化机制，导致新基因或基因功能的出现。肌肉生长抑制素（MSTN）是肌肉生长的负调控因子，在硬骨鱼类中，由于基因组复制，MSTN 以双拷贝的形式存在。本研究通过比较亚洲鲈鱼（Lates calcarifer）在经历禁食应激时的组织调控，为鱼类 MSTN 基因家族的分化提供了证据。结果表明，在营养剥夺后，L. calcarifer 的肌肉、肝脏、鳃和脑中存在差异表达和特定的组织反应。特别是，LcMstn-1 在肝脏（约 4 倍）和肌肉（约 3 倍）中表达增加，而在大脑（约 0.5 倍）和鳃（约 0.5 倍）中表达减少，而 LcMstn-2 在大脑和肌肉中保持稳定，在鳃（约 2.5 倍）和肝脏（约 2 倍）中上调。Mstn 基因家族的差异表达得到了调控元件的计算机分析的支持，这些分析至少在基因的上游近端区域揭示了 Mstn-1 和 Mstn-2 之间的分化。特别是 Mstn-1 在种间表现出更高的保守性，表明该基因在分类群中可能具有高度保守的功能。
