利用线粒体COI和微卫星标记分析文蛤7个地理群体的遗传变异

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 利用线粒体COI和微卫星标记分析文蛤7个地理群体的遗传变异 DOI: 10.5846/stxb201409151822 作者: 作者单位: 国家海洋环境监测中心,大连海洋大学,国家海洋环境监测中心,辽宁医学院,国家海洋环境监测中心,国家海洋环境监测中心 作者简介: 通讯作者: 中图分类号: 基金项目: 国家海洋公益项目(201305043,201305027);国家自然科学基金项目(31101899) Genetic diversity and differentiation of seven geographical populations of hard clam(Meretrix meretrix) assessed by COI and microsatellite markers Author: Affiliation: National Marine Environmental Monitoring Center,Dalian Ocean University,National Marine Environmental Monitoring Center,Liaoning Medical University,National Marine Environmental Monitoring Center,National Marine Environmental Monitoring Center Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:利用线粒体细胞色素氧化酶亚基I(COI)和微卫星标记分析了文蛤7个地理群体(朝鲜新义州,辽宁丹东、蛤蜊岗和盘山,山东东营,江苏如东和启东)的遗传多样性和群体分化。PCR扩增获得142条602 bp的COI核苷酸片段,比对到13个变异位点,包括11个转换和2个颠换,定义了22个单倍型,共享单倍型12个,新义州、丹东和启东群体分别拥有特有单倍型。单倍型多样性最高的是如东群体(h=0.900),最低的是东营群体(h=0.600);核苷酸多样性最高的是丹东群体(π=0.00350),最低的是蛤蜊岗群体(π=0.00115)。基于COI数据的Fu's Fs中性检验和核苷酸不配对分析揭示文蛤种群历史上曾经历过群体扩张事件。分子变异分析(AMOVA)表明,群体内遗传变异占71.64%,群体间遗传变异占28.36%,群体间发生显著的遗传分化(P < 0.05)。7个微卫星标记扩增280个个体共获得54个等位基因,平均等位基因数为7.7个,平均观测杂合度和期望杂合度分别为0.3878和0.7996。江苏群体具有较高的遗传多样性,但7个群体间遗传多样性不存在显著差异(Kruskal-Wallis检验, P > 0.05)。Hardy-Weinberg平衡检验结果显示49个群体-位点组合中有18个偏离平衡(P < 0.05),表现为杂合子缺失。单倍型邻接(NJ)树显示聚类未展示地域性特色,但某几个同一或者相近地理群体的单倍型具有聚类现象(如东和启东部分单倍型出现地理聚类)。依据群体间遗传距离以Kimura 2-parameter为模型建立UPGMA系统发育树,显示丹东群体和江苏的如东和启东群体聚为一支,暗示江苏苗种的异地养殖已经污染丹东文蛤的遗传背景。 Abstract:The hard clam(Meretrix meretrix) is a commercially important shellfish in China. With the rapid development of the aquaculture industry of M. meretrix, the demand for seed cultures has led to the over-exploitation of natural populations, which makes stock enhancement a high priority. Stock enhancement programs that use a small number of breeders for the production of hatchery-reared juveniles to be released to the environment may have negative effects on the genetic diversity of wild populations due to a reduction in the genetic variability of the released stock. In this study, the genetic diversity of seven geographical populations(Sinuiju in North Korea; Dandong, Geligang, and Panshan in Liaoning Province; Dongying in Shandong Province; and Rudong and Qidong in Jiangsu Province) of M. meretrix was assessed using the mitochondrial cytochrome c oxidase subunit I(COI) gene and microsatellite markers. We obtained a total of 142 COI sequences. Each COI sequence was 602 bp in length. These sequences contained 14 variant sites, including 12 transitions and 2 transversions. Twenty-two haplotypes were identified, with 12 haplotypes shared among populations. Population-specific haplotypes were identified in the Sinuiju, Dandong, and Qidong population, respectively. The haplotype diversity was highest in Rudong(h=0.900) and lowest in Dongying(h=0.600). The nucleotide diversity was highest in Dandong(π=0.00350) and lowest in Geligang(π=0.00115). Neutral test(Fu's Fs) and mismatch distribution analysis revealed that the hard clam experienced a population expansion event. Analysis of molecular variance(AMOVA) indicated that 71.64% of the genetic variance was within populations and 28.36% of the variance was among populations, demonstrating significant genetic differentiation among populations(P < 0.05). A total of 54 alleles were amplified from 280 individuals by using 7 microsatellite markers, with an average of 7.7 alleles per locus. The mean observed heterozygosity(Ho) and expected heterozygosity(He) was 0.387 and 0.7996, respectively. Compared with other populations, genetic diversity in the Jiangsu population was highest, but the difference was not significant(Kruskal-Wallis test, P > 0.05). Among the 49 population-locus combinations(7 populations×7 loci), 18 cases deviated from the Hardy-Weinberg equilibrium(P < 0.05), indicating heterozygote deficiencies. The neighbor-joining tree showed that the haplotypes were not clustered according to geographical location, but some haplotypes from the same or neighboring locations grouped together(e.g. Rudong and Qidong showing geographical clustering). The unweighted pair group with arithmetic mean(UPGMA) phylogenetic tree showed that the Dandong population was grouped with the Jiangsu population, suggesting that the introduced Jiangsu clam seed has contaminated the genetic background of the Dandong population. These results highlight the need to monitor the genetic effects of releasing large numbers of juveniles. 参考文献 相似文献 引证文献