3个地理居群泥鳅的同工酶生化遗传分析

Biochemical genetic analysis of isozymes in three populations of Misgurnus anguillicaudatus

【目的】探讨3个不同地理居群(黄河、长江、珠江流域)泥鳅群体的遗传变异特性及其亲缘关系。【方法】采用聚丙烯酰胺凝胶电泳(PAGE)技术和同工酶谱分析方法,检测并分析黄河、长江、珠江流域各30尾泥鳅的10种同工酶(乳酸脱氢酶(LDH)、过氧化物酶(POD)、酯酶(EST)、α-淀粉酶(α-AMY)、苹果酸脱氢酶(MDH)、葡萄糖6磷酸脱氢酶(G6PDH)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、碱性磷酸酯酶(ALP)、ATP酶(ATPase))基因的多态性,并采用Nei’s数据处理方法分析泥鳅群体间的遗传变异特性和亲缘关系。【结果】在所分析的10种同工酶中,记录到30个基因座位,以其主要的等位基因频率低于0.99为标准,从泥鳅3个群体中各检测到7～9个多态基因位点,其多态位点比例为0.2333～0.3000,平均预期杂和度为0.05865～0.07629;3个地理居群泥鳅群体的遗传偏离指数均为负值;泥鳅种内遗传相似性很高,为0.9838～0.9965。【结论】泥鳅群体的遗传多样性在淡水鱼中处于较高水平,但其群体遗传结构不够合理,会对以后泥鳅种质资源的保护产生较大影响;3个地理居群泥鳅群体从分类上还属于同一个种群。

[Objective] This study was to investigate the genetic variation and relationship in 3 population of M. anguillicaudatus collected from the Yellow River,Yangtze River and Pearl River. [Method] 30 loach （M. anguillicaudatus） samples were collected from Huanghe, Changjiang, Zhujiang. Discontinuous vertical plate polyacrylamide gel electrophoresis （PAGE） was used to investigate the genomic polymorphism of 10 isozymes. Xiong QM＇ s method was made to analyse the patterns of Isozyme and Nei＇ s was used for statistical analysis. [Result] The results showed that 10 isozymes （EST, SOD, POD, CAT, G6PDH,α-AMY,MDH,LDH, ALP and ATPase） were coded by 30 loci, 7-9 of each 3 population were found polymorphic according to the polymorphic standard 0. 99, and the mean proportion of polymorphic loci of three populations was 0. 233 3-0. 300 0. The average predicted heterozygosity was 0. 058 65-0. 076 29,and.the genetic similarity among 3 populations was very high,0. 983 8-0. 996 5. [Conclusion] It revealed higher genetic diversity in populations of the three rivers compared with other freshwater fish. However,taking negative genetic deviation index of hardy-weinberg of all three populations into account, the present status of M. anguillicaudatus was not so good. The unconscionable genetic structure of populations of the three rivers may bring some effect in genetic divercity protection. What＇s more,it indicated all three populations belonged to one species in taxology.