人类转录假基因序列碱基片段的分析研究

Analysis Research on Basic Group Fragment of Human Transcribed Pseudogene Sequences

对人类201条转录假基因的2碱基片段、3碱基片段、4碱基片段、5碱基片段和6碱基片段进行了统计。发现所统计的碱基片段在相对频率小于2范围内的模式占总模式数的89%以上;长度较长的碱基片段(5碱基片段、6碱基片段)同三核苷酸碱基片段之间包含和被包含关系较明显;人类转录假基因序列里出现最多的碱基片段大多是由AG核组成的,稀有模式主要是以CG核组成的3碱基片段,这可能是因为转录假基因序列与其同源编码基因mRNA竞争去稳定蛋白所引起的;在人类转录假基因序列中每平均约26个碱基就有一个终止密码子模式(TAG、TAA和TGA),终止密码子的频繁出现可能是原功能基因编码区的一种容错机制。另外,进行了相对频率的统计分析,发现对于2碱基片段、3碱基片段、4碱基片段、5碱基片段和6碱基片段的研究是具有其统计意义的。

It has been carried on the statistics about 2 basic group fragments, 3 basic group fragments, 4 basic group fragments, 5 basic group fragments and 6 basic group fragments from the 201 human transcribed pseudogenes. The author found that the above 89% basic group fragments of the total are in the region of the relative frequency （RF）≤2 . It is quite obvious that the longer basic group fragments （5 basic group fragments, 6 basic group fragments ） are made up of the 3 basic group fragments. In the human transcribed-pseudogenic sequences the longer base elements mostly are composed by AG. And the rare pattern mainly has the 3 basic group fragments which is form of CG. This possibly is for as much as that the transcribed-pseudogenic sequence competes for the non-stable protein with mRNA of its homologous coding gene. Every approximate 26 basic groups have a termination-codon（TAG, TAA and TGA） equally in the human transcribed -pseudogenic sequences. This continual appearance possibly is the original functional genic coding region＇s fault-tolerant mechanism. In addition, we have carried on statistical analysis of RF, and discovered that the analysis research about 2 basic group fragments, 3 basic group fragments, 4 basic group fragments, 5 basic group fragments and 6 basic group fragments has its statistical significance.