GENETIC DIVERSITY IN THREE WILD POPULATIONS OF SHRIMP FENNEROPENAEUS CHINENSIS IN YELLOW AND BOHAI SEAS AS REVEALED BY MICROSATELLITE DNA
GENETIC DIVERSITY IN THREE WILD POPULATIONS OF SHRIMP FENNEROPENAEUS CHINENSIS IN YELLOW AND BOHAI SEAS AS REVEALED BY MICROSATELLITE DNA
复制标题
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Mengzhu Xian
中科院分区：
文献类型：
--
作者：
Mengzhu Xian
利用微卫星DNA技术对渤海湾、辽东湾和海州湾3个中国对虾野生种群的遗传多样性和遗传分化进行了研究。从三个野生种群的60个样本中提取基因组DNA。聚合酶链式反应在25μ的L反应中进行，经8%变性聚丙烯酰胺凝胶电泳法分离，银染显影。本研究旨在为中国对虾种质资源的可持续利用和种群布局提供理论依据。结果表明：对3个野生居群的遗传变异进行了7个多态位点电泳法筛选。除EN0 0 2 1(PIC=0 3174)外，每个座位的PIC均大于0 5，这与群体遗传学分析和遗传连锁图谱的构建不一致。在7个微卫星DNA座位上，从60个样本所代表的3个地理群体中获得56个等位基因。不同座位的等位基因数在3~16个之间，平均7625个，其中EN0033(16个)座位的等位基因数最高，其次是RS0683(12个)、RS0859(7个)，EN0018、EN0201和RS1101座位分别获得6个等位基因，EN0021座位仅获得3个等位基因。根据各微卫星座位的基因频率和等位基因频率计算观察杂合度(Ho)和期望杂合度(He)，平均Ho值以BH最高(Ho=0.7000，He=0.7273)，其次是HZ(Ho=0.6929，He=0.7553)和LD(Ho=0.5857，He=0.7184)。在所有种群中，平均He值均高于平均Ho值。P值检验表明，BH和HZ各有1个座位偏离Hardy_Weinberg平衡，除LD种群有1个座位偏离Hardy_Weinberg平衡外，其余2个座位均显著偏离Hardy_Weinberg平衡，但从P平均值来看，3个野生种群总体处于平衡状态(P04)。根据Nei(1972)的方法对居群间的遗传距离和遗传相似性进行了评价，结果表明，BH和LD的遗传距离最小，LD和HZ次之，BH和HZ的遗传距离最长。遗传多样性也遵循同样的趋势。用UPGMA(算术平均非加权配对组法)对3个野生种群进行聚类分析，证实BH与LD之间的亲缘关系比它们与HZ的个体距离更近。在Arlequin用AMOVA模型对3个野生种群的种群分化程度进行分析，结果表明BH和LD的多样性系数(Fst)最小，说明BH和LD种群之间的分化很小。种群分化程度介于HZ和其余两个地理种群之一(F St 0 5)之间。从变异贡献率来看，三个野生种群的变异主要来自种群内(92.83%)，而不是种群间(7.17%)。
The Microsatellite DNA technique was used to estimate genetic diversity and genetic differentiation in three wild populations of shrimp Fenneropenaeus chinensis , three of which were collected from the Bohai Sea Bay (BH), Liaodong Bay (LD) and Haizhou Bay (HZ), respectively. Genomic DNA was extracted from 60 samples for the three wild populations. PCR was performed in a 25μl reaction and isolated by electrophoresis on a 8% denaturing polyacrylamide gel and visualized by silver staining. The purpose of the study was to provide theory basis for the continuable utilization of germplasm resources and population plot of F. chinensis. Results showed: 7 polymorphic loci were screened electrophoretically for genetic variation of the three wild populations. PIC (Polymorphic Information Content) value per locus was more than 0 5 except for locus EN0021 ( PIC = 0 3174) which was not the same with the analysis of population genetics and the construction of genetic linkage map. 56 alleles were acquired from the three geographical populations represented by 60 samples at 7 microsatellite DNA loci. The numbers of alleles in different loci ranged from 3 to 16, with on average 7 625, the highest numbers of alleles were from locus EN0033 (16) followed by RS0683 (12), RS0859 (7), locus EN0018, EN0201 and RS1101 acquired 6 alleles, respectively, locus EN0021 only acquired 3 alleles. The observed heterozygosity ( H o) and the expected heterozygosity ( H e) were calculated based on frequencies of genotypes and alleles of each microsatellite locus, the average H o value was the highest with BH ( H o = 0 7000, H e = 0 7273) followed by HZ ( H o = 0 6929, H e = 0 7553) and LD ( H o = 0 5857, H e = 0 7184). In all populations, the average H e value was higher than the average H o value. The test of P values showed that 1 locus departed from the Hardy_Weinberg equilibrium in each population of the BH and HZ, 2 loci departed prominently from the Hardy_Weinberg equilibrium except that 1 locus departed from the Hardy_Weinberg equilibrium in the population of LD, but as a whole, the three wild populations were in a balanced condition according to the average value of P (P 0 4). Both genetic distance and genetic similarity evaluated between populations according to the method by Nei (1972) showed that BH and LD were of the shortest genetic distance, followed by LD and HZ, BH and HZ were of the longest genetic distance. Genetic diversity followed the same trend. Cluster analysis of the three wild populations performed with UPGMA (unweighted pair group method with arithmetic mean) confirmed the closer linkage between BH and LD than their individual distances to HZ. The degree of population differentiation between the three wild populations using AMOVA model in ARLEQUIN showed that BH and LD have the lowest value of diversity coefficient ( F st ) indicating only the slightest differentiation between the populations of BH and LD. The degree of population differentiation was moderate between HZ and one of the remaining two geographic populations ( F st 0 5). For the three wild populations, variation was mostly due to within populations (92 83%) rather than among populations (7 17%) according to the contribution rate of variation.