Institute for Cancer Genetics and Taub Institute, Department of Pathology, Columbia University Medical Center, New York, NY 10032, USA.
Am J Hum Genet. 2010 Feb 12;86(2):109-12. doi: 10.1016/j.ajhg.2010.01.021.
In this issue of The Journal, an article by Schalkwyk et al.(1) shows the landscape of allele-specific DNA methylation (ASM) in the human genome. ASM has long been studied as a hallmark of imprinted genes, and a chromosome-wide version of this phenomenon occurs, in a random fashion, during X chromosome inactivation in female cells. But the type of ASM motivating the study by Schalkwyk et al. is different. They used a high-resolution, methylation-sensitive SNP array (MSNP) method for genome-wide profiling of ASM in total peripheral-blood leukocytes (PBL) and buccal cells from a series of monozygotic twin pairs. Their data bring a new level of detail to our knowledge of a newly recognized phenomenon-nonimprinted, sequence-dependent ASM. They document the widespread occurrence of this phenomenon among human genes and discuss its basic implications for gene regulation and genetic-epigenetic interactions. But this paper and recent work from other laboratories(2,3) raises the possibility of a more immediate and practical application for ASM mapping, namely to help extract maximum information from genome-wide association studies.
在本期《 杂志》中，Schalkwyk 等人的一篇文章展示了人类基因组中等位基因特异性 DNA 甲基化（ASM）的全景。ASM 长期以来一直被作为印迹基因的标志进行研究，并且在女性细胞的 X 染色体失活过程中，这种现象以随机的方式在整个染色体范围内发生。但 Schalkwyk 等人研究的 ASM 类型有所不同。他们使用高分辨率、甲基化敏感 SNP 阵列（MSNP）方法，对一系列同卵双胞胎的外周血白细胞（PBL）和口腔细胞中的 ASM 进行全基因组分析。他们的数据为我们对新识别的现象——非印迹、序列依赖性 ASM 的认识带来了新的细节。他们记录了这种现象在人类基因中的广泛发生，并讨论了其对基因调控和遗传-表观遗传相互作用的基本影响。但这篇论文和其他实验室的最近工作(2,3)提出了 ASM 图谱更直接和实际的应用的可能性，即帮助从全基因组关联研究中提取最大信息。
