茶树EST-SNP分布特征及标记开发

对NCBI网上公开的12757条茶树ESTs序列进行聚类,成功构建了茶树的独立基因（Unigene）数据库,发现茶树的EST序列冗余率约为68.2%。初步建立了茶树EST-SNP标记开发体系,明确了茶树EST中SNP的分布规律,茶树编码区的SNP发生频率约为0.58%,平均200bp就有1个SNP位点,并进一步推算出茶树基因组DNA序列的杂合率约为0.38%,平均300个碱基就可能出现1个杂合位点。从237个多基因聚类簇中发现了818个SNP候选位点,设计了25对SNP引物进行DNA重测序验证,发现EST-SNP候选位点的多态检出率为75%。

Characterization of EST-derived SNPs and Development of SNP-markers in Tea (Camellia sinensis)

By clustering the 12 757 ESTs of tea downloaded from NCBI,a unigene database of tea was successfully built.It was found that the redundancy rate for ESTs from tea was approximately 68.2%.An EST-SNP exploiting system for tea was established preliminarily.The SNP distribution was identified.The occurrence frequency for coding region SNP in tea was appropriately 0.58%.It meant that there was average one SNP in every 200 bp of tea ESTs.Furthermore,the hybrid rate for tea genome was deduced to be 0.38%,averagely one hybrid DNA site per 300 bp.Totally 818 candidated SNP were exploited from 237 multigene clusters.Then 25 pairs of SNP primers were designed and 75% of these sites were validated to be polymorphism by DNA sequencing.