DNA methylation at the putative promoter region of the human dopamine D2 receptor gene

DNA methylation was investigated in the putative promoter region of the hum an dopamine D2 receptor gene (DRD2). Twenty-two DNA samples from two types of cells differentially expressing D2 receptors, striatum and lymphocytes, were subjected to bisulphite modification-based mapping of methylated cytos ines. In the tested region, the DNA from lymphocytes exhibited a significan tly higher degree of methylation than that from striata. In addition, a sig nificantly higher proportion of methylated to unmethylated cytosines was de tected in DRD2 from the right than the left striatum, and a trend towards a greater degree of methylation was detected in older than in younger indivi duals. These DRD2 methylation findings are consistent with dopamine D2 rece ptor binding data from the literature which support the idea that DNA methy lation plays a role in regulation of DRDZ expression. (C) 1999 Lippincott W illiams & Wilkins.