College of LAS « Illinois

Entomology

Honeybee Brains

bees

Gene may be responsible for changing food-gathering behavior of bees.

A new discovery in the brain of honeybees has an LAS researcher suggesting that the gene he studied has played a key evolutionary role in the changes of food-gathering behaviors in many creatures.

Honeybees live in a social world of distinct age-related divisions of labor. Many begin their adult lives, inside the hive, as sanitation workers or nursemaids. By two to three weeks of age, they take flight and begin foraging. Bees make this transition through a series of gradually widening orientation flights, during which times their brains undergo several changes. Research by Gene Robinson, an entomologist and neuroscientist in LAS, and his colleagues have shown that behavioral changes are driven by increased gene activity.

Honeybees' transition from nursemaids to foragers is helped along by an increase in the activity of the foraging gene FOR. This gene stimulates an activity-boosting enzyme, called PKG, in some of the brain's visual processing centers.

Two forms of FOR previously had been found to influence foraging behavior in flies. "Rover" flies that cover large areas have high levels of PKG, while "sitter" flies that gather food nearby have low levels. PKG also has been linked to feeding arousal in some other invertebrates and vertebrates. The behavior of nurse bees loosely resembles that of sitter flies, while forager bees display rover-like behavior.

"The fact that at the molecular level there is a loose analogy between sitter flies and nurse bees on one hand and rover flies and foragers on the other hand is interesting for two reasons," says Robinson. "First, it supports the idea that FOR may have had an evolutionary role in the changes of food-gathering behaviors in many creatures. Second, these changes are over vastly different time scales—an evolutionary time scale in flies and a maturational or developmental one in bees."

Spring 2003