DNA methylation is a process carried out by methyl transferases, were in methyl groups are added to cytosine or adenine nucleotides on genetic material. It is known to affect gene expression and X-chromosome inactivation etc. This process is exclusively found in almost every organism, with some exceptions and is important in epigenetic tool.
Recently a paper was published in Nucleic Acids Research that highlighted the differences in methylation status of genetic material (DNA) in brain cells. Two different types of brain cells namely, neuronal and non-neuronal cells, obtained from six Caucasian males with no known medical history of psychiatric condition, were used for the study. Epigenetic modification like methylation of DNA serves as an imperative step in the nervous system development and hence methylation profiling of the DNA can help in answering many queries related to the subject.
This particular research has established it that in both neuronal and non-neuronal cells methylation of DNA is distally positioned from the TSS. For neuronal cells a distinct pattern of methylation of DNA has been found to be only one of its kind for neuronal cells. Moreover Non-CpG methylation has been found to be more frequent in former cell type than the latter. It could be established from the paper that non-CpG methylation is exceedingly regulated course of action that might have a vital role in regulating cell-specific epigenetic regulation.
Nucleic Acids Research doi: 10.1093/nar/gkt838.