Researchers have shown how epigenetic changes interact with genes to modulate feeding behavior in fruit flies. The study was led by scientists at CIFAR’s Child and Brain Development program and published yesterday in PNAS.
The “foraging gene” in fruit flies influences whether flies tend to be “rovers” that forage for food or “sitters” that wait for it. The researchers isolated gene products and identified which ones were important for shaping rover or sitter behavior. They found that the epigenetic regulator G9a is necessary for rover-sitter differences. It interacts with the foraging gene by adding methyl groups to proteins associated with one of the gene’s promoters. Rovers had a higher incidence of methylation causing a decrease in the promoter’s RNA expression.
Interfering with RNA transcripts specific to one of the foraging gene promoters caused a reversal of phenotype, changing sitters into rovers, further demonstrating the association between RNA transcription and foraging behavior.
While humans have their own version of the foraging gene, this type of study would not be feasible for a human subject. Nevertheless, the researchers hope fruit fly models can be used for future epigenetic studies to model human behaviors and get a clearer picture of how human environments shape behavior.
Image: Front view of a fly, the fly brain is outlined in the head, with a string of DNA wrapped around histones spiraling out. In front of the fly is a blue sugar drop, the food used in the study’s feeding behavior experiments. Image courtesy of Ina Anreiter, University of Toronto.