AMOUNT AND DISTRIBUTION OF 5-METHYLCYTOSINE IN HUMAN DNA FROM DIFFERENT TYPES OF TISSUES OR CELLS
AMOUNT AND DISTRIBUTION OF 5-METHYLCYTOSINE IN HUMAN DNA FROM DIFFERENT TYPES OF TISSUES OR CELLS
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DOI：
10.1093/nar/10.8.2709
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发表时间：
1982-01-01
影响因子：
14.9
通讯作者：
GEHRKE, C
中科院分区：
文献类型：
--
作者：
EHRLICH, M;GAMASOSA, MA;GEHRKE, C
对7个不同的正常人体组织和8个不同类型的同质人类细胞群体的DNA总碱基组成的分析表明，胞嘧啶残基的甲基化程度在组织特异性和细胞特异性方面存在相当大的差异。甲基化程度最高的两个DNA分别来自胸腺和脑，5-甲基胞嘧啶(M5C)的摩尔百分比分别为1.00和0.98%。活体来源中甲基化程度最低的两种DNA是胎盘DNA和精子DNA，其M5C的摩尔百分比分别为0.76和0.84。两组样本之间的差异有统计学意义(P<；0.01)。6个人类细胞系或品系的DNA的M5C含量从0.57%到0.85%不等。还测定了再解离动力学分离的DNA的主要和次要的碱基组成。除精子DNA外，M5C在这些组分中的分布随组织或细胞类型的变化很小或没有变化。在每种情况下，与未分离的DNA相比，非重复的DNA序列都是低甲基化的。
Analysis of the total base composition of DNA from seven different normal human tissues and eight different types of homogeneous human cell populations revealed considerable tissue-specific and cell-specific differrences in the extent of methylation of cytosine residues. The two most highly methylated DNAs were from thymus and brain with 1.00 and 0.98 mole percent 5-methylcytosine (m5C), respectively. The two least methylated DNAs fromin vivosources were placental DNA and sperm DNA, which had 0.76 and 0.84 mole percent m5C, respectively. The differences between these two groups of samples were significant with p<0.01. The m5C content of DNA from six human cell lines or strains ranged from 0.57 to 0.85 mole percent. The major and minor base composition of DNA fractionated by reassociation kinetics was also determined. The distribution of m5C among these fractions showed little or no variation with tissue or cell type with the possible exception of sperm DNA. In each case, nonrepetitive DNA sequences were hypomethylated compared to unfractionated DNA.