缢蛏微卫星多态性分析及其在亲子鉴定中的应用

Analysis of microsatellite polymorphism and its application in parentage determination of Sinonovacula constricta

摘要:

利用磁珠富集法，构建了缢蛏（Sinonovacula constricta）微卫星富集文库。开发并筛选出18对微卫星引物，其中8对微卫星引物亲缘排除率较高，选取这8对引物对家系进行了亲子鉴定。结果表明，18对微卫星引物在12个个体中等位基因为2~6，平均等位基因为3.00；观测杂合度在0~1.000之间，平均值为0.581 3；期望杂合度0.290~0.779，平均值为0.528 4；多态信息含量为0.239~0.703，平均值为0.432 2。当两个亲本基因型未知时，8对微卫星引物在整个家系中单个亲本排除率（E-1P）为0.583~0.916，平均值为0.790 0；当一个亲本基因型已知时，另一个亲本的排除率（E-2P）为0.406~0.830，平均值为0.653 9。同时可知在子代个体数量不断增加的情况下，排除率仍在较高范围，因此可以作为亲子鉴定的分子标记。这对于缢蛏规范化养殖、家系选育的开展具有重要意义。

Abstract:

The Microsatellite-enhanced genomic library of Sinonovacula constricta was constructed using magnetic beads enrichment method. A total of 18 pairs of microsatellite primers were developed and screened out, of which 8 pairs showed high levels of genetic polymorphism. With these 8 pairs, the parentage determination was estimated and evaluated. The result revealed that, for the 18 pairs of microsatellite primers in 12 individuals, the number of alleles ranged from 2 to 6 and the average was 3, the observed and expected heterozygosis varies from 0 to 1.000, and from 0.290 to 0.779, respectively, and the polymorphism information content (PIC) changed from 0.239 to 0.703. The single parent exclusion rate(E-1P)was 0.583 to 0.916 if parents were both unknown, while that was 0.406 to 0.830 when only one of the parental genotype was known. Meanwhile, it was identified that with the increasing number of offspring, the exclusion rate of these markers still remains in a higher range. Thus, these pairs can be applied as microsatellite markers for identifying progeny genetic relationship, which is beneficial and significant for Sinonovacula constricta standardized cultivation and pedigree breeding.