All animals communicate with each other using chemical signals. These signals allow animals to assess their environment and to find food, potential mates, and escape from predators. Understanding how animals recognize and respond to these chemical cues is essential for a better understanding of animal development and behavior. We are studying animal-to-animal communication in a laboratory animal, the roundworm C. elegans. C. elegans emits a complex mixture of chemicals that acts as a crowding signal for other worms. The goal of this project is to explore how C. elegans detects and responds to this crowding signal. Specifically, the goal is to identify the nerve cells and the proteins present in them (receptors) that detect these chemicals, and to investigate how detection of this information alters the development and behavior of these animals. Understanding this critical process will provide key information on chemical communication among animals, as well as between animals and their environment. This project will provide the basis for a doctoral thesis and one to two undergraduate senior honors research theses. Graduate and undergraduate students will be trained in the experimental and theoretical basis of genetics, behavioral studies, genomics and molecular biology, and will be provided the opportunity to present their work at local and national forums. This work will also foster interactions between biologists, physicists and biological chemists.
This NSF-funded project led to the identification of the molecular and neuronal pathways by which the soil nematode C. elegans responds to chemical signals emitted by other members of its species. Intraspecific chemical communication is a critical feature of the lifecycle of many organisms; this signaling regulates mating, reproduction, aggression and survival. In this project, we identified receptor proteins that recognize specific chemicals emitted by other nematodes. Animals mutant for these proteins fail to respond to a large number of nematode-specific chemicals and exhibit defects in development. We also characterized the neuronal circuits that allow nematodes to be attracted towards, or avoid, chemicals produced by other nematodes. These findings will impact not only our understanding of animal lifecycles, but may also lead to strategies for the control of nematode pest species. This project led to the training of several undergraduate and graduate students, as well as postdoctoral fellows. K-12 students were also involved in this work, as were students belonging to underrepresented groups. As part of this project, we established collaborations with chemists, physicists and engineers to design new methods for examining animal behavior and development. Concepts from this work were disseminated broadly both to scientists and to non-scientists (zookeepers). This work also led to several scientific publications.
