Reading the DNA Methylation Signal (original) (raw)

1. A. BIRD and
2. D. MACLEOD
3. Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom

Excerpt

A cell's properties depend largely on its pattern of geneexpression. During the development of complex multicellular organisms, multiple cell lineages emerge amongthe descendants of the single zygotic cell. Within eachlineage, the range of gene expression programs is effectively restricted, culminating in the definitive program ofthe final differentiated cell. As part of this process, somegenes are selected for future activity, whereas others aredisqualified by long-term silencing. For a specific gene inone cell type, silence versus activity is not determinedsolely by the available combinations of transcripion factors in that cell, but also by local differentiation of chromatin structure near to or including the gene. A key feature of such local differentiation of the genome is itsstability within and between cell generations. The studyof these processes has come to be known as epigenetics.Contemporary epigenetics might therefore be defined as,"the study of the structural adaptation of chromosome regions so as to perpetuate local activity states....