水稻胚乳特异表达基因的挖掘及顺式元件分析

Mining the endosperm-specific genes and analysing the cis-regulatory elements in Rice

本研究旨在利用计算机方法对水稻胚乳特异性表达基因进行挖掘和功能分析,及特异性顺式调控元件的预测。我们将基因在不同组织中的表达信号谱看作多维空间内的向量,利用向量夹角余弦法计算其与理想状态下该基因在某一组织特异表达向量的相似度,以此来判断组织特异性表达基因。本文通过对水稻芯片数据的大规模分析,共挖掘出了127个在水稻胚乳中特异表达基因。并对其启动子进行顺式元件预测,发现两个与胚乳特异表达相关的顺式调控元件,其保守序列分别为CATGCATSCM和GATCGATCGR。与已知功能的顺式元件比较显示,前者为种子特异基因表达相关的RY repeat元件,而后者则与元件RNFG1相似,但其具体功能尚不明确。

This study aimed to discover the rice endosperm - specific genes and cis - acting regulatory elements by in silico approach. The gene expression data in different tissue was viewed as a vector in a hyperspaee, and the tis- sue specificity of the gene was determined by calculating the cosine of the angle between the actual expression vec- tor and the perfect tissue - specific expression vector. A total of 127 endosperm - specific genes were identified by analyzing microarray expression data using this method. Prediction of cis - acting elements showed that two motifs with the conserved sequences CATGCATSCM and GATCGATCGR were enriched in the promoters of the endosperm - specific genes. The former motif is similar to the RY repeat known to be involved in tissue - specific gene expres- sion in seed; the latter is similar to the RNFG1 element, but the detailed function is still unknown.