基于转录组数据的铜藻微卫星标记开发与验证

Development and verification of SSR based on transcriptome of Sargassum horneri

根据铜藻转录组测序数据来进行微卫星标记的发掘,共获得2 800个微卫星位点。二碱基重复出现的次数最多,占32.82%,其次是三碱基重复,占25.21%;在所有重复单元类型中,AC/GT出现频率最高,占9.18%;重复序列的长度则主要集中在12~20 bp,占72.79%;重复次数主要集中在5~10次,占74.14%。随机选取74对引物进行验证,最终获得18个具有多态性的微卫星标记。对31株铜藻个体进行检测和评价,共扩增得到43个等位基因,每个位点平均等位基因数为2.39,平均有效等位基因数为1.91,平均观测杂合度(H_o)为0.318,平均期望杂合度(H_e)为0.449,平均多态信息含量(PIC)为0.365,在18个位点中有11个显著偏离Hardy-Weinberg平衡(P<0.05)。开发的微卫星标记为后续铜藻多样性、起源和迁移等遗传学问题研究提供了有力支撑。

SSRs were developed and characterized by using transcriptome data.A total of 2800 SSR loci were identified and dinucleotides were the most frequent(32.82%),followed by trinucleotides(25.21%).AC/GT was the most abundant unit(9.18%).The length of repetitive sequences was mainly concentrated between 12-20 bp(72.79%),and 5-10 repeats being the most abundant number(74.14%).74 pairs of primers were randomly selected for detection,and 18 polymorphic SSRs were obtained finally.The characteristics of these microsatellites were determined in 31 individuals of S.horneri.A total of 43 alleles were detected,the allele number per locus ranged from 2 to 4(average 2.39),and mean effective allele number was 1.91,and mean observed and expected heterozygosity were 0.318 and 0.449,respectively.The average of polymorphism information content(PIC)was 0.365,and 11 loci deviated significantly from Hardy-Weinberg equilibrium(HWE)(P<0.05).These obtained SSR markers will be helpful for the genetic studies in S.horneri.