作　　者： ; ; ; ; ; ; ; ;

机构地区： 香港科技大学

出　　处： 《中国生物工程杂志》 2011年第6期38-48,共11页

摘　　要： 虽然表达序列标签(ESTs,mRNA片段序列)已广泛用于高效基因发现和补充基因组注释的工作,最近,与实时荧光定量反转录PCR(qRT-PCR)结合,它也开始应用于种系遗传学、转录谱及其蛋白组学方面。通过对油料木本植物小桐子(J.curcas)的生殖组织基因表达水平的分析,预期可能找到一些与油脂合成相关的基因。这些研究成果在将来可能用于提高种子产油木质类植物的油产量。为此,分别构建了两个cDNA文库,一共得到9289条平均长度为603bp的EST序列。这些序列经过组装得到4502条独立基因序列(UniSeqs),分别包括1427条重叠群(包含1条以上EST序列)和3075条单一序列(包含1条EST序列)。用Gene Ontology(GO)分类软件对这些组装的序列进行了基因注释,并利用qRT-PCR对其中50条EST序列在叶子,花和种子中的相对表达水平进行了定量分析,发现在两个cDNA文库中有6条高丰度的EST序列(Contig1452,Contig1482,Contig1510,Contig1514,Contig1534和Contig1535)在一或两个小桐子组织中也是高表达。这些基因编码高表达的油脂合成相关蛋白或者转录因子。此实验为小桐子的基因组注释及其在增加公共数据库内储备序列的数量方面提供了EST序列。尤其是实时荧光定量反转录PCR分析验证的6条在cDNA文库中频繁出现的,高丰度的,具有推定功能的EST序列,特别是qRT-PCR检测出的与油脂合成或转录因子相关的EST编码基因群可能在小桐子的油脂合成中起着重要的作用。 The expressed sequence tags （ESTs） , fragments of mRNA sequences, have been widely used for effective gene discovery and complementation of the genome annotation. It is also beginning to be applied in the fields of phylogenetics, transcript profiling and proteomics recently in combination with quantitative real-time RT-PCR （qRT-PCR）. The analysis of genes expression level from reproductive organs of the oilseed-bearing shrub called Jatropha curcas （J. curcas ） may reveal some interesting genes related to regulation of lipid biosynthesis. The outcome may someday be used to improve the oil productivity of oil seed-bearing woody plants. Two cDNA libraries were constructed separately. A total of 9289 EST sequences were obtained with an average length of 603 bp （base pair）, where as 4502 unique sequences （UniSeqs） were obtained with assembly of these EST sequences, including 1427 contigs （containing more than one reads） and 3075 singletons （containing a single read）, respectively. These assembled sequences were annotated with gene names of Gene Ontology （GO） terms. In these annotated UniSeqs, the relative expression level of 50 ESTs was quantified with qRT-PCR in tissues of leaf, flower and seed. It was found that the most abundant 6 ESTs （Contig1452, Contig1482, Contigl510, Contigl514, Contig1534 and Contig1535）, which are frequently detected, in two cDNA libraries were also expressed highly in one or two different tissues. These highly expressed genes encode lipid biosynthesis- related proteins or transcript factors. Numerous high quality ESTs for J. curcas genome annotation and increase in the number of sequences deposited in public databases were provided. The qRT-PCR assay has validated the abundance of six interesting ESTs, which were frequently found in cDNA library. Especially, those genes, which are related to both lipid biosynthesis and transcription, have been shown to be actively expressed according to qRT-PCR analysis. These genes may play an important role in rezulatio

关 键 词： 小桐子 麻疯树 表达序列标签 实时荧光定量反转录 测序 生殖组织 油脂合成

领　　域： [生物学]