微卫星DNA标记在大口黑鲈亲权鉴定中的应用

Application of microsatellite makers for parentage determination in Micropterus salmoides

【目的】探讨微卫星DNA标记在大口黑鲈(Micropterus salmoides)亲权鉴定中的可行性,为大口黑鲈家系选育的系谱精确鉴定和选育效果评价提供依据。【方法】选择12个多态信息含量较高的微卫星DNA位点,以人工选育建立的大口黑鲈5个全同胞家系为试验材料,采用Cervus 3.0进行亲权分析,并根据家系内个体间的遗传距离进行UPGMA聚类分析。【结果】所选的12个微卫星DNA多态位点在102个子代中的平均等位基因数(A)为3,平均观测杂合度(Ho)为0.594 8,平均期望杂合度(He)为0.545 7,平均多态信息含量(PIC)为0.475 9。Cervus3.0亲权分析表明,在置信度为95%时,使用12个和10个位点,模拟和实际分析的判别成功率分别为96%和98%,87%和91%;而置信度为99%时,分别为78%和92%,64%和86%;在置信度为99%和95%时,判别准确率皆在90%以上。从12个位点中挑选10个多态信息含量高的微卫星DNA位点,即可将102个子代完全准确地聚为5个群体。亲权分析结果与聚类分析结果一致。【结论】所选用的12个微卫星位点可用于大口黑鲈亲权鉴定研究,其判定成功率和准确率较高,结果可靠。

【Objective】 This study was initiated to assess the feasibility of parentage determination by microsatellites in order to give help for family accuracy determination and estimate the results of selective breeding in aquaculture populations for largemouth bass（Micropterus salmoides）.【Method】 12 genotypes of the most polymorphic microsatellites loci were detected in 5 full-sib families of selected largemouth bass（Micropterus salmoides） and the parentage determination was done by using the software package Cervus 3.0. The UPGMA dendrogram was constructed according to genetic distance among 102 individual of 5 families. [Result] The basic genetic parameters of the 12 microsatellite polymorphic loci in offspring population were.the average number of alleles A= 3, Mean observed heterozygosity Ho=0. 594 8, Mean expected heterozygosity He= 0. 545 7, Mean polymorphic information content PIC= 0. 475 9. Simulations based on allele frequency data from the population demonstrated that 10 loci were required to assign 64% and 86% of offspring with 99% confidence,87% and 91% of offspring with 95 % confidence in simulation and actual simulation analysis respectively. When marker data from 12 loci were used, the assignment rate of offspring to their true parental couple （including 7 males and 7 females） increased to 78% and 92% with 99% confidence,96% and 98% with 95% confidence in simulation and actual simulation analysis respectively. The power of microsatellite loci was not only estimated by the assignment success rate, but also judged by assignment accuracy rate. When 10 microsatellites were used, the assignment accuracy rate was more than 90%;when all loci were used,the assignment accuracy rate was close to 100%. The UPGMA tree demonstrated that when only 10 most polymorphic loci were selected,the results were consistent with parentage determination and the records of the 5 families. [Conclusion] The results of this study revealed that the microsatellite markers could be used in the parentage determination of largemouth bass with high assignment rate and accuracy.