雌核发育棕点石斑鱼EST-SSR的开发验证

Development and Verification of EST SSRs Based on Transcriptome of the Gynogenetic Epinephelus fuscogutatus

通过人工雌核发育棕点石斑鱼( Epinephelus fuscogutatus)的转录组序列,共获得了24 359 个微卫星位点,棕点石斑鱼转录组的微卫星重复基序具有不同的分布特征,其中以单碱基( 34. 05 %)、二碱基( 37. 58%)和三碱基( 22. 75 %)为主要的EST-SSR基序重复类型.根据微卫星引物设计原则,随机筛选了93 个EST-SSR位点来进行引物合成和多态性检测,最终开发了48 个具有多态性的微卫星标记,并在不同棕点石斑鱼群体中进行了初步的验证.结果显示:每个位点等位基因数( Na)为2 ~ 22,平均等位基因数为9;观测杂合度( Ho)为0. 111 ~ 1. 000,期望杂合度( He)为0. 636 ~ 0. 940;多态信息含量( PIC)为0. 538 ~ 0. 922 个,表明48 个EST-SSR位点均表现出高多态性( PIC > 0. 5).结果表明:基于雌核发育棕点石斑鱼转录组数据,开发微卫星标记是可行的.本研究所开发的具有多态性的微卫星标记可应用于棕点石斑鱼及其近缘种的遗传多样性分析和分子标记辅助育种研究.

In the report,a total of 24, 359 microsatellite loci were obtained from artificial gynogenetic Epinephelus fuscogutatus transcriptome. Mononucleotide,dinucleotide and trinucleotide repeats were the main types,which was 35. 05%,37. 58%,22. 75% of the total SSR ,respectively. According to the design principles of microsatellite primers,93 EST SSR loci were randomly selected for primer synthesis and polymorphism detection. 48 polymorphic microsatellite markers were developed and used in different E. fuscogutatus groups. The results showed that the number of alleles ( Na) was ranged from 2 to 22,with an average of 9 alleles /locus. The observed heterozygosity ( Ho) was ranged from 0. 111 to 1. 000,and the expected heterozygosity ( He) was ranged from 0. 636 to 0. 940. The polymorphism information content ( PIC) was ranged from 0. 538 ~ 0. 922,indicating that 48 EST SSR loci showed high polymorphism ( PIC > 0. 5). This results indicated that EST sequences produced by transcriptome sequencing was an effective source to develop SSR markers. It was feasible to develop microsatellite markers based on transcriptome data of the gynogenetic E. fuscogutatus,and the developed microsatellite markers with polymorphism could be applied to genetic diversity analysis and molecular marker-assisted breeding research of E. fuscogutatus and sibling species.