基于非标记蛋白质组学技术筛选影响察哈尔羊肌肉品质的重要分子标记

为研究察哈尔羊不同部位肌肉蛋白质组成差异及差异蛋白功能，通过数据信息依赖性获取与SWATH非标记蛋白组学定量技术，对察哈尔羊背最长肌和臀肌进行蛋白质鉴定和定量分析，并对其进行生物信息学分析。结果表明：察哈尔羊背最长肌和臀肌肌肉中共检测到蛋白质1 073 个，筛选出差异蛋白140 个，其中背最长肌中高表达差异蛋白116 个，低表达差异蛋白24 个；背最长肌中高表达差异蛋白GO（gene ontology）功能富集分析结果表明，在细胞组分中，富集于细胞外外泌体中的蛋白质最多，其次富集于细胞膜内，在分子功能中，蛋白质主要参与分子内转移酶活性、聚RNA结合和L-乳酸脱氢酶活性过程，在生物学进程中，蛋白质主要参与碳水化合物代谢过程、肌节组织和肌肉收缩过程；通过差异蛋白的网络互作分析发现，肌纤维组成模块包括肌球蛋白-11、肌球蛋白-1（myosin-1，MYH1）、肌间蛋白-1、肌球蛋白-2（myosin-2，MYH2）、肌球蛋白-8（myosin-8，MYH8）、肌球蛋白轻链激酶-2、肌球蛋白轻链-2、肌钙蛋白T-3、视松蛋白和肌球蛋白结合蛋白C等蛋白质，肌球蛋白MYH1、MYH2、MYH8有望成为影响肉品质的重要分子标记。

Screening for Important Molecular Markers Affecting Meat Quality of Chahar Sheep Based on Label-Free Proteomics

In order to study the difference in the protein compositions of different muscles in Chahar sheep and the functions of differential proteins, the identification and quantitative analysis of proteins in Longissimus dorsi and Gluteus of Chahar sheep were carried out using information dependent acquisition (IDA) and label-free proteomics based on sequential windowed acquisition of all theoretical fragment ions (SWATH). Then, bioinformatics analysis was performed. A total of 1 073 proteins were detected in the two muscles including 140 differential proteins. In total, 116 up-regulated and 24 down-regulated proteins were found in Longissimus dorsi. Gene ontology and pathway enrichment analysis showed that the up-regulated proteins were most abundant in the exosome followed by the cell membrane; they were mainly involved in the molecular functions of intramolecular transferase activity, RNA binding and L-lactate dehydrogenase as well as in the biological processes of carbohydrate metabolism, sarcomere and muscle contraction. The network interaction of these differential proteins showed that muscle fiber component module consists of a variety of proteins, including myosin-11, myosin-1 (MYH1), myomesin-1, myosin-2 (MYH2), myosin-8 (MYH8), myosin light chain kinase-2, myosin light chain 2, troponin T-3, telethonin, and myosin-binding protein C. MYH1, MYH2 and MYH8 are expected to be important molecular markers affecting meat quality.