白桦EST-SSR信息分析与标记的开发

对NCBI(美国国立生物技术信息中心)中2 5 48条欧洲白桦ESTs的序列进行分析,结果表明:其中260条ESTs中含有306个SSRs,为全部 ESTs序列的10.2%,SSR频率为12.01%.其中,二核苷酸重复比例为81.37%,三核苷酸重复比例为16.67%,四核苷酸重复比例为1.96%.不同软件设计引物的效率不同,Pri mer3设计出176对SSR引物,在白桦中扩增成功的引物比例为59.09%,而具有多态性的引物比例仅为25.96%;SSR Primer设计出100对引物,在白桦中扩增成功的引物比例为37%,而具有多态性的引物比例为48.65%.

Data Mining for SSRs in ESTs and EST-SSR Marker Development in Betula platyphylla

Through the sequence analysis of 2 548 ESTs in Betula pendula deposited in NCBI,we found that 306 SSRs were distributed in 260 ESTs out of 2 548 ESTs sequences,accounting for 10.2% of the whole EST sequences.The frequency of SSR was 12.01%,in which,the repetitive proportions of dinucleotide,trinucleotide,and tetranucleotide were 81.37%,16.67%,and 1.96%,respectively.Moreover,the efficiency of primer design with various softwares was different.The software,Primer3,designed 176 pairs of SSR primers,the proportion of primers,which were successfully used for amplifying DNA fragments of B.platyphylla,was 59.09%,and the proportion of primers that produced polymorphic fragments was 25.96%.The software,SSR primer,designed 100 pairs of primers,the proportion of primers,which were successfully used for amplifying DNA fragments of B.platyphylla,was 37%,and the proportion of primers producing polymorphic fragments was 48.65%.