在低盐度胁迫下鲻幼鱼鳃丝Na^+-K^+-ATP酶活性及其β亚基mRNA表达与显微结构变化  

Effects of low salinity stress on Na^+-K^+-ATPase activities,expression of Na^+-K^+-ATPase β-subunit mRNA and microscopical structure in gill filaments of juvenile Mugil cephalus

作　　者：李磊[1] 蒋玫[1] 王云龙[1] 吴庆元[2] 牛俊翔[2] 沈新强[1] 

机构地区：[1]中国水产科学研究院东海水产研究所,上海200090 [2]上海海洋大学海洋科学学院,上海201306

出　　处：《浙江大学学报（农业与生命科学版）》2014年第2期223-230,共8页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家重点基础研究发展计划(973计划)资助项目(2010CB429005)

摘　　要：探讨在低盐度胁迫下鲻(Mugil cephalus)幼鱼鳃丝Na+-K+-ATP酶活性、Na+-K+-ATP酶β亚基mRNA表达量变化以及对鳃丝组织显微结构的影响.结果表明:在盐度分别为20(对照组),15,10,5和0实验条件下,20d后各低盐度组鳃丝Na+-K+-ATP酶活性均高于对照组;0和5盐度组鳃丝Na+-K+-ATP酶活性在实验过程中表现为持续上升的趋势,前期升高幅度大,后期升高幅度减小;10和15盐度组鳃丝Na+-K+-ATP酶活性在15d后达到峰值,至20d呈现小幅下降趋势.鳃丝Na+-K+-ATP酶β亚基mRNA表达的变化趋势与Na+-K+-ATP酶活性的变化趋势基本保持同步,显示出了其对Na+-K+-ATP酶活性的调控作用.对鳃丝显微结构观察的结果显示,随着盐度的降低,鲻幼鱼鳃小片逐渐变宽,伴随间距缩小,同时泌氯细胞数量逐渐减少,体积缩小,扁平细胞体积增大,黏液细胞数量增多.这表明在低盐度胁迫下鲻幼鱼鳃的生理功能和组织结构具有随外界水体盐度变化的适应能力.Summary In natural aquatic system,salinity can largely influence growth,breeding,and even fishes survival. In general, euryhaline fishes often possess strong osmotic adjustment capacity. The gill filaments play an important role in the maintenance of blood ion and acid-base balance in seawater-acclimated fishes,especially if there is a sudden change in water salinity.Seawater-acclimated fishes drink seawater to counter osmotic loss of water,and secrete excess Na＋ and Cl- across the gill filaments.When there is a change between freshwater and seawater,euryhaline fishes must transform their gill filaments from an ion-absorbing epithelium to an ion-secreting epithelium,or vice versa.Associated with this transformation is change of Na＋/K＋-ATPase activity,Na＋/K＋-ATPase gene expression and structural change of the gill.Euryhaline teleost fishes,such as killifish Fundulus heteroclitus and Mozambique tilapia Oreochromis mossambicus ,have been used as model animals for the study of osmo-and ion-regulation in teleost fish.However,there are little accumulating researches and available literature on juvenile Mugil cephalus .Thus,the objective of the present study is to explore the response and adjustment mechanisms of juvenile M.cephalus to salinity stress. The present study examined the effects of low salinity stress （salinity 1 5,10,5,0,and salinity 20 as control） on Na＋-K＋-ATPase activities,expression of Na＋-K＋-ATPase β-subunit mRNA and structural changes in the gill filaments of juvenile M.cephalus during the experimental period of 20 days. 〈br〉 The results showed that no fish mortality occurred for all experimental groups during the study period.The Na＋-K＋-ATPase activities in the gill filament tissue were significantly lower in the control group than in the treatment groups.At the low salinity groups （0 and 5）,the Na＋-K＋-ATPase activities showed rising trends by high and low amplitude during the early and later experimental period,respectively,and the activities at salinity 10 an

关 键 词：鲻幼鱼 盐度 鳃丝 NA^+-K^+-ATP 酶 显微结构 

分 类 号：S965.2[农业科学—水产养殖] X171[农业科学—水产科学]