Interspecific Analysis for SNPs in EST Libraries of Oil Palm- Elaeis Guineensis and E. Oleifera

Oil palm is the second largest source of edible oil, which contributes to approximately 20% of the world's production of oils and fats. Expressed sequence tag (EST) sequencing programs have provided a wealth of information, identifying novel genes from a broad range of organisms and providing an indication of gene expression level in particular tissues. It also provides the richest source of biologically useful SNPs due to the relatively high redundancy of gene sequence, the diversity of genotypes represented within databases, and the fact that each SNP would be associated with an expressed gene. There are cultivated two species of oil palm, Elaeis guineensis Jacq. from tropical western Africa and E. oleifera from Americas. Interspecific SNP detection carried but by choosing Lambda Zap II libraries of both species. Auto_snp perl script was used to cluster the ESTs and detect SNPs. A total of 163 EST sequences belong to Lambda zap libraries analysed here, interestingly we have found 60 SNP site (35 Transition transversion 25 ) in this species specific sequences. Labda Zap tissue also shows the similar pattern of SNPs, such as transition type mutation is higher than trasnversion type in Oil palm (Riju et al, 2007).油棕是全球第二大食用油脂来源，约占全球油脂总产量的20%。表达序列标签（expressed sequence tag, EST）测序计划已积累了海量研究信息，可从广泛的生物类群中鉴定新基因，并能反映特定组织内的基因表达水平。由于基因序列的相对高冗余度、数据库中涵盖的基因型多样性丰富，且每一个单核苷酸多态性（single nucleotide polymorphism, SNP）均与表达型基因相关联，因此EST也是获取具有生物学价值的SNP的最丰富来源。目前已培育的油棕共有两个物种，分别是源自西非热带区域的油棕（Elaeis guineensis Jacq.）以及原产于美洲的美洲油棕（E. oleifera）。研究人员通过构建两个物种的Lambda Zap II文库，开展了种间SNP检测。本研究采用Auto_snp Perl脚本对EST序列进行聚类分析，并以此检测SNP位点。本次研究共分析了163条来自Lambda Zap文库的EST序列，值得注意的是，在这些物种特异性序列中，我们共发现60个SNP位点，其中包含35个转换型突变与25个颠换型突变。Lambda Zap相关序列同样呈现出相似的SNP分布模式，即油棕中的转换型突变频率显著高于颠换型突变（Riju等，2007）。