Tasheva E S, Roufa D J
Division of Biology, Kansas State University, Manhattan, 66506.
Somat Cell Mol Genet. 1993 May;19(3):275-83. doi: 10.1007/BF01233075.
Previously we described a recurrent, site-specific G4784 --> A transition mutation affecting exon V of the Chinese hamster ovary cell RPS14 gene. Because the mutation is located within a CpG dinucleotide, we considered the possibility that deoxycytidine methylation might be responsible for the transition's unusually high frequency and site specificity. Therefore, we used a procedure based on the PCR amplification of bisulfite-modified genomic DNA to analyze the pattern of DNA cytosine methylation in exon V of the CHO cell RPS14 locus. Our data indicate that the CpG dinucleotide targeted by the transition mutation is stably methylated in CHO cell chromosomes. This finding supports the notion that deoxycytidine methylation promotes "spontaneous", site-specific transition mutations in mammalian cells.
此前我们描述了一种复发性、位点特异性的G4784→A转换突变，该突变影响中国仓鼠卵巢细胞RPS14基因的外显子V。由于该突变位于一个CpG二核苷酸内，我们考虑了脱氧胞苷甲基化可能是导致该转换异常高频率和位点特异性的原因。因此，我们使用了一种基于亚硫酸氢盐修饰的基因组DNA的PCR扩增程序，来分析CHO细胞RPS14基因座外显子V中的DNA胞嘧啶甲基化模式。我们的数据表明，转换突变所靶向的CpG二核苷酸在CHO细胞染色体中是稳定甲基化的。这一发现支持了脱氧胞苷甲基化促进哺乳动物细胞中“自发”的、位点特异性转换突变的观点。
