应用改良甲基化间区位点扩增(AIMS)技术对人类全基因组CpG岛甲基化谱的分析

目的进行人类全基因组CpG岛甲基化谱分析。方法采用改良甲基化间区位点扩增(AIMS)技术，以甲基化敏感和甲基化不敏感的3组同裂酶进行分析。分析6％、8％、10％3种变性测序胶对于分析人类甲基化谱电泳条带的影响，3种酶切组合的分析效果以及进行放射自显影和分子成像系统分析的对比。结果得到具有个体差异的人类基因组CpG岛甲基化图谱，为后续研究奠定了基础。6％变性测序胶所得电泳条带的分辨率和条带范围明显优于8％和10％变性测序胶。3种酶切组合均可以很好地进行AIMS分析。放射自显影和Personal Molecular Imager FX分子成像系统两种方法相辅相成。结论改良AIMS技术是一种甲基化高通量分析方法，具有简单、特异、易操作的特点。所选3组内切酶组合可以较全面的覆盖人类CpG岛，使分析结果更加准确，且所需的基因组量少，可满足临床微量标本检测的需要。

Genome-wide analysis of DNA methylated status of CpG islands with the modified AIMS technology

Objective To conduct the global assessment of methylated DNA status of CpG islands. Methods The modified AIMS (amplification of inter-methylated sites) technology was adopted, which mainly included 3 groups of isoschizomers (methylation-sensitive and methylation-insensitive restricted enzymes). The comparison analysis of methylome among 3 concentrations (6%, 8%, 10%) of polyacrylamide with 8M urea denaturing sequencing gel and the digestion effect among 3 groups of isoschizomers were carried out. The results of personal molecular imager FX system and autoradiography were also compared. Results Genome-wide detection of methylome of CpG islands might be the technical basis for the subsequent analysis. The resolving power and scope bands in 6% polyacrylamide denaturing sequencing gel were superior to those in gels with the other two concentrations. 3 groups of isoschizomers could meet the need of genome-wide detection of methylome of CpG islands. Personal molecular imager FX system and autoradiography could be used together, and they compensated each other. Conclusions The optimized AIMS technology is a kind of high-throughput method to analyze methylome, which is simple, specific, and easy to handle. The 3 groups of isoschizomers can cover most of CpG islands for genome-wide detection and get the ideal results. Only a small quantity of genome DNA is enough to meet the need of clinical detection.