甲基化DNA对突变的alkA基因转录的影响

The Effect of Methylated DNA on Transcription of Mutational alkA Gene

目的：认识在适应应答反应中ａｌｋＡ基因表达活性与ｍＤＮＡ的关系，研究ｍＤＮＡ对突变ａｌｋＡ基因体外转录的影响。方法：以突变的ａｌｋＡ基因启动子为模板，观察ｍＤＮＡ对其体外转录产生ｍＲＮＡ量的影响。结果：ａｌｋＡ基因启动子转录体系中加入ｍＤＮＡ，产生的ａｌｋＡｍＲＮＡ是未加ｍＤＮＡ的对照组的１～８倍；ｌａｃ基因启动子转录体系中加入ｍＤＮＡ产生的ｌａｃｍＲＮＡ与对照组基本相同。结论：ｍＤＮＡ对ｌａｃ基因启动子转录无明显影响，而对突变型和野生型ａｌｋＡ基因启动子转录有明显促进作用。

Objective:This paper was to investigate the relationship between the expression activity of alkA gene and Methylated DNA (mDNA) in adaptive response and to study the effect of mDNA on the transcription of mutational alkA gene in vitro.Methods:The promoter of mutational alkA gene was used as a templated to observe the effect of mDNA on the transcription of mutational alkA gene in vitro. Results: The amount of alkA mRNA was 1～8 times in the mDNA group as high as that in the controlled group. The amount of Lac mRNA did not differ significantly between the two groups with and without mDNA. Conclusions:The transcription of Lac gene is not regulated by mDNA, but the transcription of promoters of alkA gene (both mutational and wild types)is efectively regulated by mDNA in the promoter region.