Researchers at the University of Illinois have used an innovative approach to reveal the molecular basis of altruistic behavior in wasps. The research team focused on the expression of behavior-related genes in Polistes metricus paper wasps, a species for which little genetic data was available when the study was begun. Their findings appear today online in Science Express.
Like honey bee workers, wasp workers give up their reproductive capabilities and focus entirely on nurturing their larval siblings, a practice that seems to defy the Darwinian prediction that a successful organism strives, above all else, to reproduce itself. Such behaviors are indicative of a eusocial society, in which some individuals lose, or sacrifice, their reproductive functions and instead work to benefit the larger group.
Behavioral scientists have long noted the similarity between the maternal behaviors of some wasps and the nurturing and provisioning activities of workers. Until now, no study had uncovered a genetic link between the two.
The researchers found that the pattern of behavior-related genes expressed in the brains of worker wasps was most similar to that seen in foundresses, the female wasps who alone build new colonies and devote much of their early lives to maternal tasks.
These wasps start out as single moms, said postdoctoral researcher Amy Toth. They dont have any workers to help them, so theyre responsible for laying all the eggs and provisioning the developing larvae which then turn into workers.
The researchers selected this species because it appears to represent an evolutionary transition. Once a foundress has raised a first generation of workers, she turns over the task of nurturing the larvae to the workers and devotes herself entirely to her queenly reproductive function.
At this point, the researchers discovered, behavioral gene expression in her brain changes, becoming distinct from that see
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign