tailieunhanh - Báo cáo khoa học: Epigenetics: differential DNA methylation in mammalian somatic tissues

Epigenetics refers to heritable phenotypic alterations in the absence of DNA sequence changes, and DNA methylation is one of the extensively studied epigenetic alterations. DNA methylation is an evolutionally con-served mechanism to regulate gene expression in mammals. | ỊFEBS Journal MINIREVIEW Epigenetics differential DNA methylation in mammalian somatic tissues Hiroki Nagase1 2 and Srimoyee Ghosh2 1 Advanced Research Institute for the Sciences and Humanities Nihon University Tokyo Japan 2 Department of Cancer Genetics RoswellPark Cancer Institute Buffalo NY USA Keywords cancer CpG islands differentially methylated region differentiation DNA methylation epigenetics mouse restriction landmark genomic scanning RLGS tissuespecific DMR Vi-RLGS Correspondence H. Nagase Advanced Research Institute for the Sciences and Humanities Nihon University Nihon University Kaikan Daini Bekkan 12-5 Goban-cho Chiyoda-ku Tokyo 102-8251 Japan Fax 81 3 3972 8337 Tel 81 3 3972 8337 E-mail nagase-hiroki@ Received 30 November 2007 revised 28 January 2008 accepted 11 February 2008 doi Epigenetics refers to heritable phenotypic alterations in the absence of DNA sequence changes and DNA methylation is one of the extensively studied epigenetic alterations. DNA methylation is an evolutionally conserved mechanism to regulate gene expression in mammals. Because DNA methyation is preserved during DNA replication it can be inherited. Thus DNA methylation could be a major mechanism by which to produce semistable changes in gene expression in somatic tissues. Although it remains controversial whether germ-line DNA methylation in mammalian genomes is stably heritable frequent tissue-specific and disease-specific de novo methylation events are observed during somatic cell development differentia-tion. In this minireview we discuss the use of restriction landmark genomic scanning together with in silico analysis to identify differentially methylated regions in the mammalian genome. We then present a rough overview of quantitative DNA methylation patterns at 4600 Notl sites and more than 150 differentially methylated regions in several C57BL 6J mouse tissues. Comparative analysis between mice and humans suggests that