5-羟甲基胞嘧啶

5-羟甲基胞嘧啶（5-Hydroxymethylcytosine，简称5hmc）是生物DNA中由胞嘧啶（C）衍生而来的一种核碱基，其化学式为C₅H₇N₃O₂^[1]，可能有调控基因表现的功能，为表观遗传学上重要的碱基。5hmc最早于1952年在噬菌体DNA中被发现^[2][3]，可能为噬菌体避免被细菌限制酶切割的一种机制，有些细菌则演化出可切割含5hmc序列的限制酶（如PvuRts1I）^[4]。1972年此碱基首度在哺乳类DNA中被发现，2009年有研究在人类与小鼠的脑组织DNA和胚胎干细胞的DNA中发现5hmc^[5][6]，目前已知大多数的哺乳类细胞中可能均含有5hmc，但含量不一，在中枢神经系统的神经元^[7][8][9]及原生殖细胞^[10]中较多，且含量可能因年龄而变化^[7][11]。5hmc的具体功能尚不清楚，可能与DNA去甲基化（英语：DNA demethylation）（促进基因表现）有关^[12][13]。

5-羟甲基胞嘧啶
IUPAC名 4-Amino-5-(hydroxymethyl)pyrimidin-2(1H)-one
识别
CAS号	1123-95-1  Y
PubChem	70751
ChemSpider	63916
SMILES	C1=NC(=O)NC(=C1CO)N
InChI	1/C5H7N3O2/c6-4-3(2-9)1-7-5(10)8-4/h1,9H,2H2,(H3,6,7,8,10)
InChIKey	RYVNIFSIEDRLSJ-UHFFFAOYAT
ChEBI	76792
性质
化学式	C5H7N3O2
摩尔质量	141.13 g/mol g·mol⁻¹
若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

2012年，芝加哥大学的何川实验室发表了可对基因组中5hmc进行测序的技术TAB-seq^[14][15]。

参考文献

• 分子与细胞生物学主题

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