Local researchers abuzz for bee genome publication

With the honeybee genome about to be completed, work is ramping up in Assoc Prof Ben Oldroyd's laboratory at the University of Sydney to take advantage of the information it offers.

Oldroyd and his collaborator Prof Ross Crozier at James Cook University have just been awarded a $600,000 grant from the Australian Research Council for a study of the genetic basis of collective behaviour using the forthcoming bee genome. The genome is expected to be published soon, with a gene chip for easier screening likely to follow in short order.

"There are a number of behaviours in colonies that are collective, including thermoregulation, hygienic behaviour and the dance language," Oldroyd said. "We're interested in how this is regulated at the genetic level."

In a colony of honeybees, the queen bee mates with around 20 drones, giving rise to a colony of half sisters. This has provided clues to the genetic control of behaviour like thermoregulation, where the bees use their wings to fan air through the hive.

"As the temperature starts to rise, one subfamily starts to fan its wings, then another," Oldroyd said. "We think it involves a genetically controlled set point that differs in each subfamily."

Another behaviour with evidence of genetic control is the much-studied dance language. Honeybees perform several different dances -- a round dance which notifies bees of nearby food or nest sites, and a waggle dance which is more complex and provides information about where to find more distant sites of interest, with a transition dance providing a bridge between the two main dance forms.

Several different dialects of the dance language exist, with the transition occurring at different distances from the hive. Oldroyd suspects that genes are involved in determining the distance at which the dance changes from one form to the next.

He has been using backcrossed varieties of different races of honeybees to narrow down the genes involved. "We have a few hot candidates at the moment. The bee genome will speed things up," he said.

In another genomic project, Oldroyd has been studying the evolution of worker bee sterility. In a colony of bees, only the queen bee is able to lay eggs, and worker bees are sterile. But now and then, a worker gains the ability to lay eggs again -- so-called anarchistic behaviour.

According to Oldroyd, there are at least two genes involved in maintaining the sterility phenotype, and up-regulation of a number of factors is evident. It appears to be a reversible mechanism, allowing selection of non-sterile workers in the research environment.

Using a line of bees obtained from a Sydney beekeeper, the lab has been studying the phenomenon, which significantly affects colony organisation.

"The whole colony is completely hopeless -- all the workers stop working and lay eggs," he said. "It's an evolutionary dead end, but the fascinating thing is that it is still out there. There is always an evolutionary benefit for a worker to lay eggs, so it's a trade-off between the colony and the individual."

Oldroyd believes that the study of honeybee society and behaviour offers a window into how creatures perceive the world around us.

"[Evolutionary biologist] John Maynard Smith has argued that the last major evolutionary transition was from single organisms to colony organisms," he said. "The honeybee society is one of the few model societies that we have to play with."