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Iowa State Researcher Studies Interaction of Genes and Environment
July 24th, 2012
AMES, Iowa — Iowa State University researcher Amy Toth finds the social interactions of the wasps she studies remarkably similar to those of humans.
“In terms of social behavior, they’re the most human-like insects,” she said. “They live in small groups, and each wasp has a specific role and position in the cooperative group, similar to human social circles. They also recognize one another as individuals. And, like humans, infighting and competition among wasps is common.”
Toth has studied paper wasps for about five years. They are the black-and-yellow-bodied wasps that get their names from the papery nests with hexagonal cells they construct to house their young.
The assistant professor in Iowa State’s Department of Ecology, Evolution and Organismal Biology, recently was awarded two National Science Foundation grants, totaling $756,000, to continue her studies of the insect.
One project studies the evolution of social behavior in the insect, and the other focuses on the genetic mechanisms that regulate paper wasp behavior. Both grants focus on a specific genus, Polistes.
"Paper wasps have been studied for more than 100 years, so scientists know a lot about their social behavior, but not about their genetics," Toth said.
This is an ideal time to be studying the genomes of insects, she said. Technological advances are allowing genome sequencing to be done relatively easily and cheaply, giving researchers access to increased genetic information and presenting opportunities for new insights and discoveries.
Specifically, Toth is researching how social environment and maternal behavior impact larval development. She is applying genomic technologies to research what types of genetic changes happen during wasp development to make a queen or a worker.
By feeding and nurturing larvae differently, the mother can have a profound influence on how each develops. Mother wasps drum their antennae on the nest cells of developing larvae, and Toth and colleague Robert Jeanne at the University of Wisconsin are testing how these vibrations affect whether the larvae emerge as queens or workers, and what kinds of genetic changes accompany this process.
"There are no genetic differences between queens and workers," Toth said, "It's all about the flexibility of the genes."
Toth says preliminary data, collected in collaboration with postdoctoral researcher Susan Weiner, suggest that there may be important “epigenetic” changes to the paper wasps’ genomes during development, or environmentally induced changes to DNA that don’t affect its sequence, but affect which genes are expressed and how they’re utilized.
Through wasps, Toth is gaining insights into how environment influences genomes. "People talk about nature versus nurture, but really it’s almost always both: a constant interaction between environment and genes. Nurture directly affects nature," she said.
And while focused on wasps, Toth said these studies have wider implications.
“Studying the interplay between the environment, genes and behavior doesn’t end with wasps — the same principles can be applied to humans and other animals,” Toth said. “This research will help us better understand the flexibility of genomes and how small changes during development can have huge long-term impacts.”