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三种鯻科鱼类同工酶组织特异性及群体遗传结构分析

2015-10-20张健东何国清陈刚

张健东 何国清 陈刚 等

摘要采用聚丙烯酰胺垂直板不连续电泳法对3种鯻科鱼类6种组织(脑、眼、心、肾、肝和肌肉)的9种同工酶(ADH,EST,GDH,LDH,MDH,ME,POD,SDH,SOD)进行分析,结果显示具有明显组织特异性.此外,对每种鱼40个个体的肝脏的8种同工酶进行群体遗传结构分析,共记录15个基因位点,其中呈多态性的位点有 2个(mPod1,sSod1),多态座位比例(P)为0.133,位点平均有效等位基因数(Ae)分别为1.004,0.997和1.015,平均每个位点预期杂合度(He)值分别为0.068,0.066和0.045,平均每个位点实际杂合度(Ho)值分别为0.098,0.083和008.与其他鱼类研究结果相比较,表明3种鯻科鱼类的遗传多样性居于中等水平.

关键词鯻科鱼类;同工酶;组织特异性;遗传结构

中图分类号S917.4文献标识码A文章编号10002537(2015)05002708

The TissueSpecificities of Isozymes and the Genetic

Structure in Three Species of Theraponidae

ZHANG Jiandong1,2*, HE Guoqing1, CHEN Gang1,2, TANG Baogui1,2,

PAN Chuanhao1,2, ZHOU Hui1,2, Huang Jiansheng1,2

(1.Fisheries College, Guangdong Ocean University, Zhanjiang 524025, China; 2. Key Laboratory of Aquaculture in South

China Sea for Aquatic Economic Animal, Regular High Education Institute of Guangdong Province, Zhanjiang 524025, China)

AbstractHorizontal starch gel electrophoresis was used to investigate the tissuespecificities of isozymes and the genetic structure of Theraponidae. 9 isozymes (ADH, EST, GDH, LDH, MDH, ME, POD, SDH and SOD) in 6 kinds of tissues (brain, eye, heart, kidney, liver and muscle) of three Theraponidae species were screened and the results showed that the screened isozymes displayed remarkable tissuespecificities. Besides, 8 enzymes from liver tissues in 40 individuals were selected for the genetic analysis. The 8 isozymes systems were encoded by 15 loci, and 2 (mPod1 and sSod1) of them were polymorphic. The proportion of polymorphic loci was 0.133. The average effective numbers of alleles (Ae) were 1.004(at T.jarbua),0.997 (at T.theraps) and1.015(at P.quadrilineatus), respectively. The mean expected heterozygosities per locus (He) were 0.068, 0.066 and 0.045. The mean actual heterozygosities per locus (Ho) were 0.098,0.083 and 0.08, respectively. This result indicated that there was a middle level of genetic variation in Theraponidae.

Key wordsTheraponidae; Isozyme; tissue specificity; genetic structure

鯻科鱼类(Theraponidae) 属硬骨鱼纲(Osteichthyes),鲈形目(Perciformes),鲈亚目(Percoidei),为热带区沿岸性鱼类,主要分布于印度西太平洋地区及澳洲、新几内亚、印尼等沿岸海域[1].常见种类有细鳞鯻(Therapon jarbua)、鯻(Terapon theraps)、列牙鯻(Pelates quadrilineatus)和尖吻鯻(Rhynchopelate oxyrhynchus)4种,在中国发现了4属8种[24],鯻科鱼类肉质鲜美香滑,经济价值高,有很大的市场开发潜力[56].

同工酶在生物界广泛存在,变异丰富,且呈共显性遗传,能比较客观地代表基因组的变异,因而能较客观地度量群体的遗传变异大小,且实验条件较为简单,成本较低,结果快速可靠等优点,该技术已成为一种经济有效的群体遗传学研究手段,是近20年来检测遗传多样性研究最普遍的方法[710].本实验研究了3种鯻科鱼类部分同工酶的组织特异性并探讨其群体生化遗传结构,以期为该物种的种质调查提供有价值的生化遗传参数,同时也为种质资源的合理开发利用和遗传育种等提供部分理论依据.