Hendriks R W, Kraakman M E, Mensink R G, Schuurman R K
Department of Immunohaematology E3-Q, University Medical Center, Leiden, The Netherlands.
Hum Genet. 1991 Nov;88(1):105-11. doi: 10.1007/BF00204939.
The degree of methylation at the 5' and 3' CCGG sequences flanking the variable number of tandem repeat (VNTR) region of the DXS255 locus at Xp11.22 was analysed separately in several haematopoietic cell lineages. The 5' CCGG site on active chromosomes was found to be completely methylated in B and T lymphocytes and granulocytes. Methylation of the 5' site on inactive X chromosomes differed between females (0%-60%), but was consistent in different cell lineages obtained from individual females. In contrast, methylation at the 3' CCGG site on active chromosomes was found to vary in B lymphocytes (40%-100%), whereas complete methylation was found in T lymphocytes and granulocytes. The extent of methylation on inactive X chromosomes was found to differ significantly between B lymphocytes (17%), T lymphocytes (54%) and granulocytes (82%). Thus, methylation at the 5' CCGG site seems to be primarily related to the status of X chromosome inactivation, whereas methylation at the 3' CCGG site is mainly subject to cell-lineage-specific influences.
对位于Xp11.22的DXS255基因座串联重复序列可变数目（VNTR）区域两侧的5'和3' CCGG序列的甲基化程度，在几种造血细胞谱系中分别进行了分析。发现在活跃染色体上的5' CCGG位点在B淋巴细胞、T淋巴细胞和粒细胞中完全甲基化。非活性X染色体上5'位点的甲基化在女性中有所不同（0%-60%），但在从个体女性获得的不同细胞谱系中是一致的。相比之下，发现在活跃染色体上3' CCGG位点的甲基化在B淋巴细胞中有所变化（40%-100%），而在T淋巴细胞和粒细胞中则完全甲基化。发现在非活性X染色体上的甲基化程度在B淋巴细胞（17%）、T淋巴细胞（54%）和粒细胞（82%）之间存在显著差异。因此，5' CCGG位点的甲基化似乎主要与X染色体失活状态相关，而3' CCGG位点的甲基化主要受细胞谱系特异性影响。
