前期对酵母和果蝇核糖体蛋白(Ribosomal protein,RP)基因内含子序列中的寡核苷酸分析表明,内含子中含有潜在的转录因子结合位点.为进一步发掘核糖体蛋白基因内含子参与转录调控的证据,文章首先基于频率分析方法抽提出人和小鼠核糖体蛋白基因第一内含子中高频(Over-represented)出现的寡核苷酸片段 (亦称模体,Motif),这些寡核苷酸中超过85%与已知的转录因子结合位点吻合,是潜在的转录调控元件.对抽提出的寡核苷酸进行碱基组成分析,发现95%以上的寡核苷酸富含碱基C 和G,而较少富含A 和T.从寡核苷酸在内含子中的分布情况看,它们相对靠近第一内含子的5′端,即距离基因转录起始位点和上游区域较近.推测这些特征可能与基因转录调控有关.%Previous studies from oligonucleotides in the ribosomal protein (RP) genes of the yeast and fruitfly indicated that the potential transcriptional regulatory sites are located in the introns of the genes. The transcriptional regulatory sites in introns are still poorly understood. To explore the functional significance of transcriptional regulation of introns, we extracted over-represented oligonucleotides (also known as motifs) in the first introns of the human and mouse ribosomal protein genes by statistical comparative analysis, and found that over 85% of these oligonucleotides were consistent with the known transcriptional factor binding sites, which might be potential transcriptional regulatory elements. By analyzingrn the base compositions of these elements, we found that a majority (>95%) of the detected motifs were rich in C and G and only a few of them were rich in A and T. Moreover, the oligonucleotides were close to the 5'-ends of the first introns (the distances between the motifs and the transcriptional start sites or upstream regions of genes are short). We speculated that the properties of over-represented motifs in the first introns might be associated with the transcriptional control.
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