We are interested in better understanding how chemicals control behavior. Nematodes provide a rich subject for chemical ecology, because they function in a wide range of environments and have relatively simple behaviors. Although we have had several interesting collaborative projects over the years, our primary organism for chemical ecology has been C. elegans. Despite the wealth of genetic, cellular, and anatomical information, less is known about C. elegans chemistry. For example, the existence of a pheromone that induces a dauer larval stage specialized for dispersal had been known for nearly 30 years before the first dauer pheromone was identified [Jeong et al., 2005]. Several related compounds are made by C. elegans that regulate dauer, and the next two that were discovered were ~100x more potent than the originally described compound [Butcher et al., 2007]. In collaboration with the Sternberg and Schroder labs, we discovered the mating pheromone for C. elegans and showed that it is a mixture of small molecule ascarosides that overlap with the known dauer pheromones [Srinivasan et al., 2008].
C. elegans utilizes an extensive chemical “language” that allows individuals to communicate and regulates basic behaviors such as feeding, mating, and population density control [Edison, 2009]. Hundreds of nematode ascarosides are now known [Ludwig and Schroeder, 2013], and some receptors have been identified [e.g. McGrath et al., 2011]. We still know very little about how the components work together, how the chemical signals are regulated, and receptors and other gene products that transduce signals into behavior.
We are working to understand the environmental factors that control ascaroside expression and to identify additional ascarosides in other nematode species. This information will not only add to the extensive scientific knowledge of C. elegans but may provide important new clues for the biological control of other nematode parasites of plants or animals. We are also taking a metabolomics approach to this problem and are developing a new large-scale project to map the C. elegans metabolome. The information that we obtain from this study will help us understand the biosynthetic pathways and genetic regulation associated with ascaroside signaling and function.
We have recently published an open access review paper that describes different approaches and strategies to chemical ecology studies.
- Menger RF, Clendinen CS, Searcy LA, Edison AS, & Yost RA (2015) MALDI Mass Spectrometric Imaging of Caenorhabditis elegans. Current Metabolomics 3:130-138.
- Clendinen, C. S., Pasquel, C., Ajredini, R., and Edison, A. S. (2015) (13)C NMR Metabolomics: INADEQUATE Network Analysis, Anal Chem 87, 5698-5706.
- Stupp, G. S., Reuss, von, S. H., Izrayelit, Y., Ajredini, R., Schroeder, F. C.*, and Edison, A. S.* (2013) Chemical detoxification of small molecules by Caenorhabditis elegans. ACS chemical biology 8, 309–313. Featured in C&E News, Science and Technology Concentrates, Dec 3, 2012.
- Choe, A.&, Chuman, T.&, von Reuss, S.H.&, Dossey, A.T.&, Yim, J., Ajredini, R., Kolawa, A.A., Kaplan, F., Alborn, H.T., Teal, P.E., Schroeder, F.C., Sternberg, P.W., & Edison, A.S.*“Sex-Specific Mating Pheromones in the Nematode Panagrellus redivivus”, PNAS 109, 20949-20954 (2012).
- Fatma Kaplan; Hans T Alborn; Stephan H von Reuss; Ramadan Ajredini; Jared G Ali; Faruk Akyazi; Lukasz L Stelinski; Arthur S Edison; Frank C Schroeder; Peter E Teal*, “Interspecific nematode signals regulate dispersal behavior“, PLoS One, 7(6), e38735, doi:10.1371/journal.pone.0038735 (2012).
- Srinivasan, J., von Reuss, S.H., Bose, N., Mahanti, P., Ho, M.C., O’Doherty, O.G., Edison, A.S., Sternberg, P.W.* & Schroeder, F.C.*, “A modular library of small molecule signals regulates social behaviors in Caenorhabditis elegans”, PLoS Biol 10(1): e1001237. doi:10.1371/journal.pbio.1001237 (2012).
- Robinette, S.L., Ajredini, R., Rasheed, H., Zeinomar, A., Schroeder F.C., Dossey, A.T., & Edison, A.S.*, “Hierarchical Alignment and Full Resolution Pattern Recognition of 2D NMR Spectra: Application to Nematode Chemical Ecology.”, Analytical Chemistry 83 (5), 1649–1657 (2011).
- Kaplan, F., Srinivasan, J., Mahanti, P., Ajredini, R., Durak, O., Nimalendran, R., Sternberg, P.W., Teal, P.E.A, Schroeder, F.C., Edison, A.S., and Alborn, H.T.*, “Ascaroside expression in Caenorhabditis elegans is strongly dependent on diet and developmental stage”, PLoS One 6(3):e17804, (2011).
- Kaplan, F., Badri, D. V., Zachariah, C., Ajredini, R., Sandoval, F. J., Roje, S., Levine, L. H., Zhang, F., Robinette, S. L., Alborn, H. T., Zhao, W., Stadler, M., Nimalendran, R., Dossey, A. T., Bruschweiler, R. A., Vivanco, J. M., Edison, A. S.* “Bacterial Attraction and Quorum Sensing Inhibition in Caenorhabditis elegans Exudates”, J. Chem. Ecol. 35, 878-92 (2009).
- Wang, B., Dossey, A. T., Walse, S. S., Edison, A. S., and Merz, K.M. Jr. * “Relative Configuration of Natural Products by NMR Chemical Shifts”, Journal of Natural Products 72, 709-13 (2009).
- Srinivasan, J., Kaplan, F., Ajredini, R., Zachariah, C., Alborn, H., Teal, P., Edison, A. S.*, Paul W. Sternberg, P. W.*, & Schroeder, F. C.* “A synergistic blend of small molecules differentially regulates both mating behavior and population density in Caenorhabditis elegans.”,Nature 454, 1115-1118(2008).