盐度对草鱼肌肉I型胶原蛋白的影响及作用机制

Grass carp is an important economic species in freshwater aquaculture in China. With the continuous growth in the production, how to improve the muscle quality of grass carp is an important orientation for the future aquaculture industry development. The brackish water culturing grass carp can improve its muscle quality and increase the collagen content, however, the specific effect on the collagen properties and its mechanism are not clear. In this experiment, grass carp will be cultured in different salinity water. Muscle texture measurement, muscle section observation including sarcolemma and collagen fibers, collagen content and properties analysis，are studied to summarize the specific effect on muscle collagen by culture salinity. The gene expression levels of type I collagen, TGF-β1/Smads regulatory pathway and collagen-specific molecular chaperone Hsp47 in muscle are studied, and the differences were analyzed. In addition, the protein expression levels and distribution of type I collagen, TGF-β1 and Hsp47 are studied, then combine the gene expression results to analyze the mechanism of the effect of different salinity on type I collagen in grass carp muscle. Through the above experiments, this project comprehensively studied the effect of aquaculture water salinity on type I collagen in grass carp muscle and its mechanism.

草鱼是我国重要的淡水养殖经济鱼类，随着养殖产量的提升，如何改善草鱼肌肉品质将是未来养殖产业发展的重要方向。研究发现半咸水暂养草鱼可改善其肌肉品质，同时肌肉中胶原蛋白含量明显增加，但对于胶原蛋白性状的具体影响及作用机制并不清楚。本项目通过开展不同盐度下的草鱼养殖实验，测定肌肉质构特性，观察肌肉组织学包括肌膜及胶原纤维的差异，结合生理生化的检测手法研究肌肉I型胶原蛋白的含量和相关性状，总结分析盐度对草鱼肌肉I型胶原蛋白产生的具体影响。从分子水平研究肌肉中I型胶原蛋白合成基因、TGF-β1/Smads调节通路中相关基因、胶原特异性分子伴侣Hsp47的基因表达水平，分析差异变化。同时，研究I型胶原蛋白、TGF-β1、Hsp47的蛋白表达水平与分布情况，综合探讨不同盐度对草鱼肌肉中I型胶原蛋白影响的作用机制。本项目通过以上实验比较全面地研究了养殖水体盐度对草鱼肌肉中I型胶原蛋白的影响及作用机制。

随着养殖产量的提升和人们生活水平质量的提高，如何改善鱼类肌肉品质将是未来养殖产业发展的重要方向。草鱼(Ctenopharyngodon idella)是我国重要的淡水养殖经济鱼类。研究发现半咸水暂养草鱼可改善其肌肉品质，同时肌肉中胶原蛋白含量明显增加，但对于胶原蛋白性状的具体影响及作用机制尚不清楚。本项目通过开展不同盐度下的草鱼养殖实验，研究了不同盐度对草鱼肌肉质构特性、肌膜微细结构及胶原纤维形态的影响差异，探究了盐度对草鱼I型胶原蛋白含量和纤维形成性能的影响及其可能的作用机制。结果表明适度养殖盐度可提升草鱼肌肉质构性能，使肌膜增多增厚并使其中胶原纤维增多且密集。同时，适度养殖盐度可提升草鱼胶原蛋白含量，增强胶原纤维形成速度并使胶原纤维直径增加。本项目初步阐明了养殖盐度可能通过TGF-β1/Smad4通路对Col1α1和Col1α2的表达进行调控影响肽链的生成，而后通过调控Hsp47的表达影响具有立体构造的I型胶原蛋白的最终形成。希望本项目能为提升养殖草鱼品质及内陆盐碱地区和沿海半咸水地区养鱼技术开发提供一定的理论基础和数据支持。