KEY POINTS:
A queen bee uses her pheromones to regulate her daughters' brain activity to ensure her own survival, a researcher has found.
Otago University zoologist Alison Mercer, whose study is being published in the international journal Science, said: "This is the first demonstration of the queen's pheromones acting directly on the brain".
The queen bee produces a pheromone from a gland near her jaws. Pheromones are chemicals found in animals that trigger a behavioural response in another animal of that species.
One of the parts of the pheromone is homovanillyl alcohol (HVA), which interacts with a neurotransmitter chemical in the brain called dopamine. Another zoologist at the university, Kyle Beggs, has described bees as a valuable model for studying the biology of the brain and basic molecular mechanisms involved in learning and memory.
"New discoveries made about how dopamine systems work in bees can be correlated back to humans," Dr Beggs said.
In a mechanism that is still not understood, the pheromone appears to block dopamine and prevent the young worker bees from avoiding negative stimuli. Worker bees, which surround and nurture the queen, are all female and drone bees are male.
To test the theory, Professor Mercer and other researchers exposed test bees to the pheromone. They found these bees could not learn to associate specific smells with negative stimuli in this case such as mild electric shocks. Professor Mercer speculated the queen bee herself might be a negative stimuli.
"It turns out the queen is blocking out the ability of the young bees to make an association between signals in their environment and any nasty outcome," she told the National Geographic magazine.
"The fact that it's affecting the learning abilities of the young bees is unexpected."
But as the young worker bees age, the pheromone's control over them wanes - a mystery still being researched.
Bees avoid the queen's pheromones in high doses; too much and the worker bees become more aggressive. But the "brainwashing" pheromone may be keeping the workers from learning that being near their queen is unpleasant.
"If the young bees could build up an aversion to their own queen, they'd stop looking after her and that would be to the detriment of the colony," Professor Mercer said.
The pheromone could be the queen's insurance against the young workers rebelling. This raised the question of what effect the pheromone had on the queen, who is immobilised as a "baby machine" during her reign.
The queen bee produces all the workers and they are all sisters, sharing half of their DNA.
Last year, Professor Mercer, Dr Beggs and biochemists Peter Dearden and Megan Wilson reported on DNA sequences which will enable new insights into bee biology, evolution and how learning and memory work at the molecular level.
- NZPA
