A new sight of epigenetics——5-hydroxymethylcytosine

5-hydroxymethylcytosine(5hmC) is a new modified base,and presents at low levels in diverse cell types in mammals.5hmC is generated by the TET(ten-eleven translocation,TET) family of enzymes through oxidation of 5-methylcytosine(5mC).5hmC can decrease the affiliation between the methyl-CpG binding domain(MBD) of methylcytosine binding proteins(MeCP) and methlated DNA,revealing it has the potential function of epigenetic gene regulation.5hmC also has been proposed as a potential intermediate in active DNA demethylation.Therefore,5hmC has attracted increasing attention from researchers and more techniques and methods are used to detect 5hmC.Studies report that 5hmC differes in different tissues and is significantly decreased in tumor tissues,which suggest it may be used as a useful molecular marker for tumor diagnosis.