草鱼的微卫星亲权鉴定

Parentage identification of grass carp (Ctenopharyngodon idella) using micro-satellites

【目的】从亲权排除率、鉴别准确率、鉴别成功率等方面评价微卫星标记鉴别草鱼亲权关系的可行性，为草鱼系谱信息的确定奠定基础。【方法】利用8个微卫星标记检测5个草鱼家系亲本（F0）及其子代（F1）的基因型，以Cervus3．0软件进行亲权鉴定，并统计微卫星位点的等位基因数（Na）、多态信息含量（PIC）、观测杂合度（H0）和期望杂合度（He）等;最后通过模拟分析和试验验证，评估8个微卫星位点最多可鉴定的亲本数及其与鉴定率、置信度之间的关系。【结果】8个微卫星位点中，当两个亲本基因型未知时，单个亲本排除率（E-1P）介于0．342-0．668，平均值为0．520;当一个亲本基因型已知时，另一个亲本的排除率（E-2P）介于0．521-0．802，平均值为0．681；一对亲本组合的亲权排除率（E-PP）介于0．711-0．937，平均值为0．847。以95％置信水平和100％鉴定率为标准，模拟分析及试验验证结果表明，所选择的8个微卫星位点最多可以鉴定598个已知性别的亲本或431个未知性别的亲本。【结论】所选的H118、H137、H165、H148、4703、C2489、H57、H81等8对微卫星标记可在生产及科研试验中用于获取草鱼系谱信息。

[Objective]To provide references for ascertaining genealogy information of grass carp, the feasibility of parentage identification of grass carp using micro-satellite markers was judged from the aspects of parentage exclusion probability, identification accuracy and identification success rate. [Method]Members of 5 grass carp generations （F1） and their parents （F0） were genotyped using 8 micro-satellite markers. Parentage identification was conducted using Cervus 3.0 software. The statistics of allele （Na） amount, polymorphic information content （PIC）, observation heterozygosity and expectation heterozygosity （Ho, Ho） of micro-satellites were obtained. Finally, the relations among the maximum identification number of parents, identification rate and confidence level of the 8 micro-satellites were assessed through simulation analysis and experimental verification. [ Result]Among the 8 micro-satellite loci, regarding the unknown parental genotypes, the exclusion probability of the first parent （E-1P） was 0.342-0.668 averaging at 0.520. Concerning the known parental genotypes, the exclusion probability of the second parent （E-2P） was 0.521-0.802 averaging at 0.681. The exclusion probability of a parent pair（E-PP） was 0.711-0.937 averaging at 0.847. Taking the confidence level of 95% and 100% identification rate as the standard, the simulation analysis and experimental verification results showed that 598 known parents and 431 unknown parents could be detected using the 8 micro-satellite loci. [Conclusion]The 8 micro-satellite loci namely H165, Hl18, H148, H137, H57, H81, 4703 and C2489 could be used to obtain family information of grass carp for production and experiments.