ENU诱变草鱼及其雌核发育后代的微卫星遗传分析

Microsatellite genetic analysis of ENU mutagenesis grass carp and gynogenesis offspring group

为了获得雌核发育ENU诱变草鱼(Cetpharyngodon idellus)群体的相关遗传参数,实验采用Partec Cy Flow倍性分析仪测定ENU诱变草鱼群体(Q群体)和雌核发育ENU诱变草鱼群体(E群体)相对DNA含量分别为24.02和23.80,二者的DNA含量接近,均为二倍体。选取28个微卫星标记对Q群体和E群体多样性进行了检测。结果表明,E群体和Q群体的平均等位基因分别为3.7143、5.1786,平均有效等位基因分别为2.1857、4.0028,平均期望纯合度分别为0.5122、0.2814,平均期望杂合度分别为0.4878、0.7186,多态信息含量(PIC)平均值分别为0.4282、0.6606。从个体在微卫星位点的纯合率分析,在E群体中,每个个体的纯合度均小于1.00,说明没有完全纯合的个体。从每个微卫星位点在群体的纯合率分析,除了微卫星位点5476,HLJC118和HLJC81外,其他位点的纯合度以不同的速率得到明显的提高。综上所述,经过减数雌核发育方法,ENU诱变草鱼群体的各微卫星位点的纯合度以不同的速率得到提升,遗传多样性明显降低,此方法可以获得纯合度较高的雌核发育ENU诱变草鱼个体,为ENU诱变草鱼良种选育提供了重要的遗传数据资料。

This study aimed to obtain the genetic parameters of gynogenetic ENU-induced mutagenesis in grass carp （Ctenopharyngodon idellus）. The relative DNA content in grass carp with ENU-induced mutagenesis （Q group） and gynogenetic ENU-induced mutagenesis （E group） was 24.02 and 23.80, respectively. The Partec Cy- Flow ploidy analyzer determined that the values were close and that the mutants were diploid. We selected 28 mi- crosatellite markers to investigate the genetic diversity of the two carp groups. Respectively, the E and Q groups had average alleles of 3.7143 and 5.1786, average effective alleles of 2.1857 and 4.0028, average expected ho- mozygosity of 0.5122 and 0.2814, average expected heterozygosity of 0.4878 and 0.7186, and average polymor- phism information content （PIC） of 0.4282 and 0.6606. The homozygous rate analysis of microsatellite loci indi- cated that the E group did not contain completely homozygous individuals, as all exhibited a degree of purity 〈1.00. The analysis also showed that homozygosity in several microsatellite loci （including 5476, HLJC81, HLJC 118） improved significantly at different rates. In summary, meiotic gynogenesis of ENU-induced mutagenic grass carp improved microsatellite homozygosity at different rates and significantly decreased genetic diversity. Thus, this method yields highly homozygous individuals that can provide important genetic data for improved selection of ENU-induced mutagenic grass carp.