微卫星用于凡纳滨对虾育种过程中亲权分析及遗传多样性的变化监测

Kinship analysis and genetic variation monitoring in Litopenaeus vannamei breeding program using microsatellite DNA markers

利用7个微卫星标记分析了6个凡纳滨对虾家系的亲本（G0）及其后代（G1）的基因型分离情况，同时对G0和G1的所有座位期望杂合度进行配对比较分析，并且通过对G1群体每个位点的F-statistics分析检验群体的遗传分化，以期对凡纳滨对虾育种进行遗传监测。结果表明：共检测到44个等位基因。G0和G1的平均每个座位的等位基因数目分别为6．14和6．27，平均期望杂合度为0．786和0．733，平均多态性信息含量为0．709和0．695。7个微卫星座位的累计排除概率为0．99，并且在有亲本存在的情况下，能够将6个家系分开。G0与G1的所有座位期望杂合度的配对比较分析结果表明G0平均期望杂合度要显著高于G1（P〈0．01）。G1各座位的遗传分化指数FST，在0．2703～0．4654，平均分化系数为0．3584。说明亚群间属于高度遗传分化。最后，根据6个家系的遗传距离，利用UPGMA法对G1个体聚类分析，结果表明亲缘关系较近的家系A和B以及C和D的相似系数很高分别各聚为一类，E和F分别聚为一类。

Genotype segregation of parents livestocks （ GO generation） and their offspring （ G1 generation ） of 6 Litopenaeus vannamei families was analyzed on basis of 7 microsatellite DNA markers. In addition, heterogeneity analysis for pairwise comparisons of expected heterozygosities （ He） of all loci between GO and G1 was carried out and genetic differentiation through F-statistics at each locus in G1 population was expected to monitor genetic variation in Litopenaeus vannamei breeding. The results showed that 44 alleles were detected in total across 7 loci assayed, mean number per locus, mean expected heterozygosity and mean polymorphism information content of GO generation were 6.14, 0.786 and 0. 709 respectively, and those of G1 generation were 6. 27, 0. 733 and 0. 695 respectively. The combined exclusion probability of 7 microsatellite markers arrived at 0.99 and could seperate all 6 families with known parent. Heterogeneity analysis for pairwise comparisons of expected He of all loci between Go and G1 indicated that He of G0 was significantly higher than G1 （P 〈0.01 ）. FST of G1 per locus ranged from 0. 270 3 to 0. 465 4 and average was 0. 358 4 which meant that genetic differentiation in its sub-population was high. The UPGMA analysis based on six families genetic distances showed all individuals of G1 generation could be classified into 4 categories. Similarly to families C and D, families A and B sharing father had high similarity coefficient and clustered together, family E and F were assigned into another group respectively.