DNA methylation with a sting: an active DNA methylation system in the honeybee.

The existence of DNA methylation in insects has been a controversial subject over a long period of time. The recently completed genome sequence of the honeybee Apis mellifera has revealed the first insect with a full complement of DNA methyltransferases. A parallel study demonstrated that these enzymes are catalytically active and that Apis genes can be methylated in specific patterns. These findings establish bees as a model to analyze the function of DNA methylation systems in invertebrate organisms and might also be important to understand evolutionary aspects of DNA methylation in higher eukaryotes.