DNA methylation patterns may differentiate between honeybees within a hive that have varying roles but are genetically very similar, reports a paper that is published this week in Nature Neuroscience.

A honeybee female embryo can, depending on what it is fed, grow up to become a queen or worker bee. Andrew Feinberg and colleagues studied two particular kinds of worker bees: nurse bees, which feed other bees, and foragers, which travel outside the hive to collect food. Though these two kinds of bees do different kinds of work, their roles are not fixed, and nurse bees can switch to foraging later in their life. In contrast, the queen bee’s behavior is fixed, and it cannot switch to being a worker.

Although there are no systematic differences in the DNA sequence making up the genes in different types of honeybees, the scientists found differences in DNA methylation patterns - which can regulate gene expression - between foragers and nurse bees. When the researchers tricked some foragers into changing their behavior and behaving like nurse bees, these methylation changes were also changed to resemble the pattern in nurse bees.

This suggests that there is a close link between the pattern of DNA methylation and honeybee social group, and provides an example of how changes to the genome that do not involve a change in the DNA sequence can also modulate behaviour.