DNA Methylation and Gene Regulation

Methylation is the only major chemical modification undergone by DNA and it occurs in most organisms. In eucaryotes methylation involves the conversion of cytosine to 5-methylcytidine and it is irreversible. The relationship between methylation and gene expression is complex, but the general finding is that heavily methylated DNA is less transcriptionally active than non-methylated DNA. In particular, methylation of specific promoter sequences is thought to be the main mechanism by which methylation decreases gene activity. A problem remains in that the DNA of some organisms such as Drosophila is not methylated and hence the universal significance of methylation having a controlling role in gene expression has not been fully established. This book presents the results of a meeting attended by many of the world’s leading researchers in this area at which they discussed the role of DNA methylation in the control of gene expression. It has contributions that will be of interest to all those biochemists, molecular biologists and developmental biologists who want to know more about this important mechanism of gene control.