The sequence specificity of vertebrate DNA methylation

The relative quantity of 5-methyl cytosine in vertebrate nuclear DNA shows species and tissue variation. To determine whether this is due to the action of species or cell specific DNA methylases the sequence specificity of the 5-methyl cytosine distribution in the DNA of a range of cells has been partially characterised. The pattern of methylation was found to be remarkably constant and indicates stringent evolutionary conservation of the characteristics of vertebrate DNA methylation.