中华绒螯蟹蜕壳过程中螯足肌肉组织学及主要蛋白质含量变化  

Changes in histology and protein content in claw closer muscle of Chinese mitten crab, Eriocheir sinensis during the molt cycle

作　　者：田志环[1,2] 焦传珍[1] 吴旭干[2] 成永旭[2] 

机构地区：[1]广东韶关学院英东生命科学学院,广东韶关512005 [2]上海海洋大学农业部淡水水产种质资源重点实验室,上海201306

出　　处：《中国水产科学》2017年第5期1072-1078,共7页Journal of Fishery Sciences of China

基　　金：国家自然科学基金项目(31572635);科技部港澳台科技合作专项项目(2014DFT30270);上海市科学技术委员会科研项目(16DZ2281200);上海高校水产学高峰学科建设项目(2015-62-0908);上海市科技兴农推广项目[沪农科攻字(2016)第1-1-8号];韶关学院生态学重点扶持学科(230079030101)

摘　　要：为探讨中华绒鳌蟹(Eriocheir sinensis)蜕皮过程中肌肉生长机制,采用石蜡切片、电镜技术及生物化学方法,以中华绒鳌蟹幼蟹为对象,研究了其蜕壳过程中螯足闭螯肌肌肉的显微结构、超微结构及主要蛋白质含量的变化。结果显示,在蜕皮间期,螯足肌纤维充分伸展,多核,横截面呈不规则圆形或者多边形;肌原纤维排列有序,具有甲壳动物骨骼肌的典型特征,A带、I带及肌质网、二联体、线粒体等细胞器清晰可见。蜕皮前期,肌纤维降解以致其横截面大小不一;肌原纤维内部降解,出现腐蚀性空洞。蜕皮之后,在肌纤维末端的肌节处于超收缩状态,这些肌节长度缩短至正常长度的50%,肌纤维典型结构消失,A带、I带模糊不易区分,但肌质网、二联体、线粒体等结构仍然完整;肌纤维中间部分的肌节结构正常如蜕皮间期。生物化学研究发现,蜕皮前后螯足肌肉中肌原纤维蛋白和可溶性蛋白含量的变化同其结构特征的变化一致。本研究结果表明,中华绒螯蟹蜕皮后螯足肌肉可能的一种生长机制是通过增加新的肌节来伸长,动物刚蜕壳后,这些新形成的肌节以超收缩的形式存在,随着动物吸水身体膨大,外骨骼伸展、硬化,这些较短的肌节由于被拉伸而达到正常肌节的长度,从而完成肌肉的生长。To characterize the changes in the protein content and tissue structure of the claw closer muscle of Eri- ocheir sinensis during the molt cycle, muscles harvested at various stages during the molt cycle were studied using paraffin section histology, electron microscopy, and biochemical methods. The results showed that the histology of the claw closer muscle changed noticeably during the molt cycle. The fibers and myofibrils were fully expanded in the inter-molt stage, and the cross-sectional area resembled an irregular circle or polygon with many nuclei under the sarcolemma. The sarcomeres were generally in register in this stage. During the later pre-molt stage, the cross-sectional area of fibers showed a wide size distribution owing to pro-ecdysial muscle atrophy, and many eroded areas appeared within the myofibrils. In the post-molt stage, the muscle fibers were compacting and shrinking. At the ends of the fibers, some sarcomeres were in a state of super-contraction, leading to the sarcomere shortening its resting length by up to 50%, whereas sarcomeres in the middle region of the fiber showed a ＂nor- mal＂ appearance, with a typical arrangement of thick and thin filaments in the inter-molt stage. Biochemical ex- periments determined that the myofibrillar protein and soluble protein content in the claw closer muscle fluctuated and the results agreed well with the observed structural changes. The results indicate that the claw closer muscle of E. sinensis may increase in length during the molt cycle by adding new sarcomeres to the ends of the myofibrils. These new sarcomeres would begin as shorter sarcomeres when the carapace is very soft immediately after ecdysis Then, as the carapace becomes hardened, the new exoskeleton would be stretched by the absorption of water and the super-contracted new sarcomeres would elongate to the length of the already-existing sarcomeres within the myofibril, resulting in muscle growth.

关 键 词：中华绒鳌蟹 螯足肌肉 组织学 超微结构 肌原纤维蛋白 可溶性蛋白 

分 类 号：S968[农业科学—水产养殖]