A rather high portion of mammalian miRNA genes are found to associate with CpG-islands. It is found that 74 of 462 (16.0%), 37 of 373 (9.9%), and 25 of 234 (10.7%) of the miRNA genes are located within 1000 bps of a CpG island for human, mouse, and rat respectively. These CpG-associated miRNA genes could be located near promoter regions as well.
This finding suggests a potential role of these miRNAs in CpG-island methylation, and gene regulation.
