Quantitative Analysis of Tet-induced Oxidation Products of 5-Methylcytosine in Human Cells and Mammalian and Plant Tissues

摘要

Active cytosine DNA demethylation is the conversion of 5-methylcytosine (5-mC) to unmethylated cytosine in a process that is independent of DNA replication. In contrast to DNA methylation that is catalyzed by specific classes of methyltransferases, molecular players involved in active DNA demethylation have long been elusive. This study is the first application of LC-MS/MS/MS, along with isotope-dilution technique, for accurate and simultaneous measurements of oxidized 5-mC derivatives in genomic DNA of cultured human cells, mammalian tissues, and plants.