1. 华中农业大学水产学院, 池塘健康养殖湖北省工程实验室, 水产养殖国家级实验教学示范中心, 湖北 武汉 430070;
2. Department of Livestock and Fisheries, Ministry of Agriculture and Forestry, Vientiane, Lao PDR
熊梅(1993-),硕士研究生,从事鱼类环境生理学研究.E-mail:1227191337@qq.com
S965
国家自然科学基金项目（31670521）；现代农业产业技术体系建设专项资金项目（CARS-45）；中央高校基本科研业务费专项资金资助项目（2662015PY119）.
Kommaly Onxayvieng
College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, National Demonstration Center for Experimental Aquaculture Education, Wuhan 430070, China1. College of Fisheries, Huazhong Agricultural University, Hubei Provincial Engineering Laboratory for Pond Aquaculture, National Demonstration Center for Experimental Aquaculture Education, Wuhan 430070, China;
2. Department of Livestock and Fisheries, Ministry of Agriculture and Forestry, Vientiane, Lao PDR
泛素-蛋白酶体系统（the ubiquitin-proteasome system，UPS）是细胞内调节蛋白质代谢的重要系统。在水温（17.0±0.5）℃下，将草鱼（的养殖密度条件进行急性拥挤胁迫。在胁迫0 h、1 h、6 h、12 h、24 h和48 h以及取消胁迫后（养殖密度10 kg/m2）的6 h和168 h采集血清和背部肌肉样品，检测血清皮质醇水平、肌肉质构特性以及和UPS相关基因表达，并定量测定了肌肉组织泛素化蛋白水平。结果表明，拥挤胁迫导致血清皮质醇含量显著上升，肌肉硬度和凝聚性显著性下降，以上各指标在取消胁迫后168 h恢复到对照水平，弹性、胶黏性、咀嚼性和回复性在恢复168 h时反而高于对照组水平；和的mRNA表达量在胁迫过程中显著性上升，胁迫后恢复168 h，还是表现出较高的表达量；处理组泛素化蛋白水平在胁迫6 h和12 h时显著升高，在恢复168 h时显著降低。研究表明，急性拥挤胁迫使草鱼产生明显的应激反应，对肌肉质构特性产生了显著性影响，同时提高了肌肉UPS的活性。经过168 h的恢复，鱼体逐渐恢复到正常生理水平，但机体UPS活性仍呈现出被激活状态。急性拥挤胁迫对草鱼生理功能和肌肉质构特性的有害影响是可逆的，建议恢复时间大于168 h以帮助鱼体重新建立UPS的稳态。
The ubiquitin-proteasome system (UPS) is an important system for regulating protein degradation and function. In order to evaluate the effects of acute crowding stress on flesh quality and UPS in fish, we randomly distributed (initial body weight:56.88 g±10.54 g) into 6 aquarium tanks (length:200 cm, wide:100 cm, depth of water:55 cm) at two stocking density (three replicates for each group). Water temperature (17.0±0.5)℃, pH (7.5±0.3) and dissolved oxygen (7.0 mg/L) were maintained at the same level in each group. Fish serum and muscle samples were collected at 0 h, 1 h, 6 h, 12 h, 24 h, and 48 h after crowding stress as well as at 6 h and 168 h after the crowding stress was removed (treatment group stocking density changed from 100 kg/m2 to 10 kg/m2). The serum cortisol, muscle texture, the mRNA expressions of , and genes related to UPS as well as the content of ubiquitinated protein in fish muscle were investigated. The results showed that the serum cortisol level significantly increased after acute crowding stress, suggesting the crowding environment led to fish stress. The serum concentration of cortisol recovered to the control level after 168 h of recovery. Crowding stress also exerted an influence on muscular texture characteristics of cultured grass carp. Muscular hardness and cohesiveness decreased significantly in grass carp suffering from cute crowding stress, and the two flesh quality indexes recovered to the level of the control group after 168 h of post-stress recovery. However, muscular adhesiveness, chewiness and resilience were significantly higher than those in the control group at the end of the experiment. Compared with the control group, the mRNA expressions of in muscle of fish stocked at the treatment group were significantly increased after 48 h of crowding stress, and then returned to the control level after 168 h of post-stress recovery. It is implied that the acute crowding environment might cause cellular stress in fish. In the UPS pathway, the mRNA levels of were significantly increased after crowding stress. The transcriptional levels of these genes did not returned to the control level after 168 h of post-stress recovery. Moreover, a significant higher content of ubiquitinated proteins occurred in the dorsal muscle of fish in the treatment group at 6 h and 12 h after crowding stress. Subsequently, there were no significant difference in ubiquitinated proteins of fish stocked at two densities, while ubiquitinated proteins in the treatment group significantly declined compared to the control group at 168 h of recovery. It was concluded that the acute crowding environment induced the stress response and altered the muscular texture as well as improved muscle UPS activity. The deleterious effects of acute crowding stress on fish physiological function and muscular texture were reversible. Post-stress recovery time should be extended more than 168 h so that the stressed fish reestablish the homeostasis on UPS.
熊梅,Kommaly Onxayvieng,李大鹏,王海珊,梁骁,汤蓉,李莉,张曦,迟巍.急性拥挤胁迫对草鱼肌肉泛素-蛋白酶体系统活性的影响[J].中国水产科学,2019,26(3):427-435
XIONG Mei, Kommaly Onxayvieng, LI Dapeng, WANG Haishan, LIANG Xiao, TANG Rong, LI Li, ZHANG Xi, CHI Wei. Effect of acute crowding stress on the ubiquitin-proteasome system in the muscle of grass carp (Ctenopharyngodon idellus)[J]. Journal of Fishery Sciences of China,2019,26(3):427-435
