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Differentially methylated regions (DMRs) are stretches of DNA in an organism’s genome that have different DNA methylation patterns compared to other samples. These samples can be different cells or tissues within the same individual, the same cell at different times, or cells from different individuals. (Note: this is different from histone modification.) DNA is methylated at a CpG site, which is a cytosine followed by a guanine. The “p” refers to the phosphate linker between them. DMR usually involves adjacent sites or a group of sites close together that have different methylation patterns between samples. However, CpG islands appear to be excluded from this as they are normally unmethylated. ==Types of DMR== There are several different types of DMRs. These include tissue-specific DMR (tDMR), cancer-specific DMR (cDMR), reprogramming-specific DMR (rDMR), imprinting- specific DMR (iDMR), and aging-specific DMR (aDMR). The identification of tDMRs provides a comprehensive survey of epigenetic differences among human tissues. An example of a tDMR would be different methylation patterns between an eye cell and a liver cell within the same individual. DMRs between cancer and normal samples (cDMRs) demonstrate the aberrant methylation in cancers. It is well known that DNA methylation is associated with cell differentiation and proliferation. Many DMRs have been found in the development stages (dDMRs) and in the reprogrammed progress (rDMRs). When one of the two parental chromosomes is methylated in a particular region, this results in an iDMR. This plays a role in epigenetics, which is discussed further in the following section. In addition, there are aDMRs, also known as intra-individual DMRs (Intra-DMRs), which are changes in global DNA methylation as the age of a given individual increases. Finally, there are inter-individual DMRs (Inter-DMRs) with different methylation patterns among multiple individuals. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Differentially methylated regions」の詳細全文を読む スポンサード リンク
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