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Expression of various genes is controlled by DNA methylation during mammalian development
Author(s) -
Ehrlich Melanie
Publication year - 2003
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.10464
Subject(s) - dna methylation , biology , methylation , gene , genetics , rna directed dna methylation , epigenetics of physical exercise , regulation of gene expression , vertebrate , enhancer , gene expression , methyltransferase , dna
Abstract Despite thousands of articles about 5‐methylcytosine (m 5 C) residues in vertebrate DNA, there is still controversy concerning the role of genomic m 5 C in normal vertebrate development. Inverse correlations between expression and methylation are seen for many gene regulatory regions [Heard et al., 1997; Attwood et al., 2002; Plass and Soloway, 2002] although much vertebrate DNA methylation is in repeated sequences [Ehrlich et al., 1982]. At the heart of this debate is whether vertebrate DNA methylation has mainly a protective role in limiting expression of foreign DNA elements and endogenous transposons [Walsh and Bestor, 1999] or also is important in the regulation of the expression of diverse vertebrate genes involved in differentiation [Attwood et al., 2002]. Enough thorough studies have now been reported to show that many tissue‐ or development‐specific changes in methylation at vertebrate promoters, enhancers, or insulators regulate expression and are not simply inconsequential byproducts of expression differences. One line of evidence comes from mutants with inherited alterations in genes encoding DNA methyltransferases and from rodents or humans with somatically acquired changes in DNA methylation that illustrate the disease‐producing effects of abnormal methylation. Another type of evidence derives from studies of in vivo correlations between tissue‐specific changes in DNA methylation and gene expression coupled with experiments demonstrating cause‐and‐effect associations between DNA hyper‐ or hypomethylation and gene expression. In this review, I summarize some of the strong evidence from both types of studies. Taken together, these studies demonstrate that DNA methylation in mammals modulates expression of many genes during development, causing major changes in or important fine‐tuning of expression. Also, I discuss previously established and newly hypothesized mechanisms for this epigenetic control. J. Cell. Biochem. 88: 899–910, 2003. © 2003 Wiley‐Liss, Inc.