基因外显子连接序列与相应内含子序列的相互作用

剪接后的内含子与相应mRNA序列的相互作用在基因表达调控过程中起着非常重要的作用。基于27个物种的核糖核蛋白基因序列，采用Smith—Waterman局域比对方法得到外显子连接序列与相应内含子序列的最佳匹配片段，分析了外显子连接序列上的匹配频率分布和匹配片段的序列特征。发现一些低等真核生物EJC结合区域的匹配频率明显低于其它区域，所有物种EJC结合区域的序列构成呈现出相对低的结构序。最佳匹配片段的平均长度和配对率分布与siRNA和miRNA的结合特征相同。推测EJC和内含子在与外显子序列结合的过程中存在相互竞争和相互协作的关系，内含子中部序列在基因表达调控过程中起着重要的作用。

Interactions between Exon-exon sequence and its corresponding intron sequence of genes

There is a kind of interaction between mRNA sequences and corresponding introns after splicing, which plays a significant role in gene expression regulation process. Based on the ribosomal protein genes of 27 genomes, Smith-Waterman local alignment method were used to obtain the optimal matching segments between exon-exon se- quences and their corresponding intron sequences. The distributions of matching frequency on exon-exon sequences and the sequence characters of optimal matching segments were analyzed. We found that matching frequency on EJC bonding region are lower obviously for some lower eukaryotes. The sequence composition of EJC bonding region shows lower composed order. The average length and the matching rate distribution of the optimal matching ele- ments are the same as siRNA and miRNA. We think that it exist a kind of competitive and cooperative relations be- tween EJC and introns in the process of bonding on exons. The intermediate section of intron sequences may play very important roles in gene regulation and gene expression.