NCBI和cDNA文库中栽培花生EST-SSR分子标记的开发及其特点(英文)

Development and Characterization of EST-SSR Markers from NCBI and cDNA Library in Cultivated Peanut (Arachis hypogaea L.)

本研究利用NCBI的GenBank数据库中公布的花生86132条EST序列以及利用高油酸品种E12所创建的cDNA文库中的12501条EST序列,对这些序列进行前期处理,总共获得非冗余且拼接较长的singleton11260条,contig9972条。通过MISA软件分析发现两个EST库中共包含有3104个SSR位点,占到总共非冗余序列的11.08%。这些SSR位点被分成二核苷酸重复、三核苷酸重复、四核苷酸重复、五核苷酸重复、六核苷酸重复以及混合核苷酸重复等,其中三核苷酸重复占的比例最多,分别占到NCBI和cDNA文库的43.0%和56.8%,二核苷酸和五核苷酸重复占到所有重复位点的第二位和第三位,六核苷酸重复的比例最少。在所有重复基序中,AG/TC重复的数量最多,分别占到NCBI和cDNA文库的8.65%和13.42%。在三核苷酸重复中,CTT/GAA出现的频率最大,分别占到6.7%和13.42%。所有这些SSR基序的长度在4～51个之间。

86 132 ESTs downloaded from GenBank in NCBI and 12 501 ESTs from cDNA library constructed by high-oil linoleic acid accession El2 were analysed. After the preprocession, there were 18 051 singletons and 9 972 contigs in the GenBank of NCBI and cDNA library. Totally 3 104 SSR loci had been screened by MISA software, accounting for 11.08% for these non-redundant ESTs. All SSR loci are divided into di-nucleotide, thi-nucleotide, tetra-nucleotide, penta-nucleotide, hexa-nucleotide and multi-nucleotide etc., and thi-nucleotide motif is the most motifs and the frequency was 43.0% and 56.8% in NCBI and cDNA libraray, respectively. The number of di- and penta-nucleotide motifs were second and third in all motifs. And the hexa-nucleotide was the least motif both in NCBI and cDNA library. In all repeat motifs nucleotide, AG/TC was the most motifs and accounted for 8.65% and 13.42% in NCBI and cDNA library, respectively. Among the tri-nucleotide repeats, CTT/GAA was the most frequent motif, accounting for 6.7% and 13.42%, respectively. The repeat unit number of SSR loci is from 4 to 51.