虾夷扇贝EST-SSR标记在栉孔扇贝中的通用性研究

Transferability of EST-SSR from Patinopecten yessoensis into Chlamys farreri

中文关键词: 虾夷扇贝  栉孔扇贝  EST-SSRs  微卫星  多态性  通用性

英文关键词: Patinopecten yessoensis  Chlamys farreri  EST-SSRs  Microsatellites  Polymorphism  Transferability

中文摘要:

      为研究虾夷扇贝(Patinopecten yessoensis)和栉孔扇贝(Chlamys farreri)的群体遗传多样性并分析其亲缘关系，对在虾夷扇贝中开发的60个EST-SSR位点在栉孔扇贝中的通用性进行了研究。结果显示，21个位点可在栉孔扇贝中扩增出特异性条带，通用性比例达35.00%，其中，17个位点具有多态性，多态性比例达28.33%。在虾夷扇贝和栉孔扇贝群体中，平均等位基因数(Na)分别为2.7647和2.3529；平均有效等位基因数(Ne)分别为1.9487和1.6350；平均观测杂合度(Ho)为0.6314和0.3333；平均期望杂合度(He)为0.4569和0.3139；平均多态信息含量(PIC)为0.3726和0.2597；Nei's (1973)基因多样性指数(I)分别为0.4493和0.3087；Shannon信息指数分别为0.7176和0.5041；固定指数(Fis)检测发现，7个位点偏离了Hardy-Weinberg平衡；遗传分化系数(Fst)为0.2398。本研究开发的21对通用性EST-SSR标记，为进一步开展虾夷扇贝和栉孔扇贝遗传多样性分析、分子辅助育种、基因发掘和种质资源评价奠定了基础。

英文摘要:

      In this study, expressed sequence tag (EST)-SSR markers were developed to investigate the genetic relationship between two commercially important scallop species, Yesso scallop Patinopecten yessoensis and Zhikong scallop Chlamys farreri. A total of 60 EST-SSRs previously developed from P. yessoensis were selected, and their cross-species amplification in C. farreri was analyzed. As a result, 21 pairs of EST-SSR primers showed unique PCR products. The interspecies transferability was calculated to be 35.00%. Among the 21 EST-SSR primers, 17 were polymorphic in the studied populations, which resulted in 28.33% transferability. In the two populations of P. yessoensis and C. farreri, the number of alleles ranged from 2.00 to 4.00, with mean allele numbers of 2.7647 and 2.3529, respectively. The mean effective number of alleles was estimated to be 1.9487 and 1.6350, while the mean observed heterozygosity was 0.6314 and 0.3333, respectively. Similar to the observed heterozygosity, the mean expected heterozygosity was higher in P. yessoensis (0.4569) than in C. farreri (0.3139). For the two populations, the diversity index was consistently higher in P. yessoensis than in C. farreri. The mean polymorphism information content was estimated to be 0.3726 and 0.2597, and Nei’s (1973) gene diversity index was calculated to be 0.4493 and 0.3087, respectively. Furthermore, Shannon’s information index in the two populations was 0.7176 and 0.5041, respectively. The genetic identity between the two species was calculated to be 0.619, with a high genetic divergence between them (0.480). Among the polymorphic markers, seven loci significantly deviated from the Hardy-Weinberg equilibrium according to the average fixation index (Fis). The genetic differentiation index (Fst) between the two populations was estimated to be 0.2398. The EST-SSR markers developed for cross-species amplification of P. yessoensis and C. farreri are important resources for the study of genetic diversity, marker-assisted breeding, gene discovery, and genetic evaluation of germplasm resources.