Erik Ragsdale, an IU biologist, has been awarded a $750,000 research grant from the National Science Foundation.
His research will focus on identifying a genetic mechanism that allows genetically identical species to develop totally different characteristics based on their environment. This phenomenon is known as polyphenism.
“Despite the potential evolutionary consequences of developmental plasticity, such as polyphenism, we still don’t know much about the genetic mechanisms of the switches controlling it,” Ragsdale said in an IU press release. “This research project will be a genetic analysis of how polyphenism responds to input from the environment and how its regulation changes over evolutionary time.”
Through his research, Ragsdale will study nematode worms. Similar to how the finches studied by Charles Darwin had beaks specifically suited to different types of seeds and insects, nematode worms have a wide array of mouthparts, perfectly tailored to certain types of food.
“These worms lead virtually every lifestyle known to animals, based upon shapes of their mouths,” Ragsdale said in a press release. “They can be vegetarians, meat-eaters, omnivores, bacteria-feeders and parasites. In nematodes with polyphenism, their feeding structures are a response to specific environments, not totally pre-determined by genes.”
The worm species in the IU study, Pristionchus pacificus, can develop different types of mouths, despite possessing the same genome, based on their environment.
If they live and grow in an environment rich in food and space to grow, P. pacificus will grow a narrow mouth for peaceably grazing upon bacteria.
Likewise, if they live and grow in an overcrowded or starved environment with limited resources, they will grow a wide mouth with large, moveable teeth, which allows them to consume other worms.
As a postdoctoral researcher at Germany’s Max Planck Institute for Developmental Biology in 2013, Ragsdale was part of the team that first discovered the gene that acts as the switch in these worms, according to an IU press release, triggering the “irreversible decision” determining how the worms will feed during their lifespan.
The research Ragsdale conducts now will build off previous research by studying the exact role of genes in switches and exploring how they interact with other genes. The research will also attempt to demonstrate their evolution in related species, including those that do not exhibit polyphenism.
Through the grant, six high school students and six high school teachers will participate in the research over the next four years. Both groups will get the chance to contribute to the research through the Jim Holland Summer Science Research ProgramTT, an intensive, weeklong research training program for underrepresented high school students pursuing careers in STEM, and the IU Biology Summer Science Institute, which pairs high school science teachers with IU researchers to develop classroom curriculum based on University research.
Taylor Telford
