Department of Poultry and Aquaculture, Institute of Animal Science, Agricultural Research Organization, Rishon LeTsiyon, Israel.
Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Front Endocrinol (Lausanne). 2020 Feb 28;11:94. doi: 10.3389/fendo.2020.00094. eCollection 2020.
The growth and differentiation factor Myostatin (MSTN, also known as GDF8) negatively regulates skeletal muscle development and growth in vertebrates. Most fish genomes contain two or more genes, which are expressed in muscle and other tissues. Yet, in the genome of Nile tilapia (), which is one of the world's most important aquaculture fish species, only one gene has previously been identified. Here, we identify a second gene in Nile tilapia. We show that it clusters phylogenetically with other piscine genes and that it shares chromosomal synteny with the human and zebrafish orthologs. We further show that is not expressed in red or white muscles of Nile tilapia, but rather that its main site of expression is the brain. To determine which physiological functions are correlated with expression, adult Nile tilapia were exposed to various environmental conditions and their effect on and expression in the brain and muscles was measured using real-time PCR. We found that the centrally- and muscle-expressed genes differ in their responsiveness to diverse challenges, suggesting differential gene- and tissue-specific regulation of their expression. Metabolic and stress marker analyses showed that the altered expression is not regulated by classical stress response. Taken together, our findings expand the understanding of the MSTN system in Nile tilapia and provide evolutionary insight into its function.
肌肉生长抑制素（MSTN，也称为 GDF8）是一种负调控脊椎动物骨骼肌发育和生长的生长分化因子。大多数鱼类基因组包含两个或更多的基因，这些基因在肌肉和其他组织中表达。然而，在世界上最重要的水产养殖鱼类之一的尼罗罗非鱼（）的基因组中，以前只鉴定出一个 MSTN 基因。在这里，我们在尼罗罗非鱼中鉴定出第二个 MSTN 基因。我们表明，它在系统发育上与其他鱼类的基因聚类，并且与人类和斑马鱼的同源基因具有染色体同线性。我们进一步表明，在尼罗罗非鱼的红肌或白肌中不表达，但它的主要表达部位是大脑。为了确定哪些生理功能与表达相关，我们用实时 PCR 测量了成年尼罗罗非鱼暴露于各种环境条件下对大脑和肌肉中基因和表达的影响。我们发现，中枢和肌肉表达的基因对不同的挑战表现出不同的反应，这表明它们的表达受到不同的基因和组织特异性调节。代谢和应激标志物分析表明，改变的表达不受经典应激反应的调节。总之，我们的发现扩展了对尼罗罗非鱼 MSTN 系统的理解，并为其功能提供了进化上的见解。
