Nematodes (commonly called worms) are the most abundant animal, and E.O. Wilson has estimated that 4 out of 5 individual animals on earth is a nematode. They inhabit virtually every ecological niche including soil, compost, salt and fresh water, and there are nematode parasites of virtually every animal and plant. Several species infect humans, including Ascaris lumbricoides, which infects around 1 billion people worldwide. Some parasites have a single host, while others have multiple hosts that are necessary for an infective life cycle.
Nematodes are extremely successful and have adapted to an extremely wide range of environments, despite having a relatively simple and highly conserved overall anatomy with a simple nervous system. Underlying their anatomical simplicity is chemical complexity, which plays vital roles in their behavior.
Thus, nematodes are biologically fascinating and also have a large impact on human health, providing great opportunities in basic biology as well as applications that might lead to improved control and treatment of parasitic infection.
The small soil nematode Caenorhabditis elegans is one of the best studied animals on earth. It was the first metazoan to have its genome sequenced. Its entire cell lineage from a single fertilized egg to an adult is known and has been related to the animal’s anatomy, and its anatomy has been comprehensively described by ultra high resolution electron microscopy. Hermaphrodites have 302 neurons and 959 somatic cells. C. elegans is particularly tractable for genetic studies, and as a result many complicated genetic pathways have been identified. The importance of these studies was recognized by the 2002 Nobel Prize in Medicine to three pioneers in the field, Sydney Brenner, Robert Horvitz, and John Sulston. The 2006 Nobel Prize in Medicine was awarded to Andrew Fire and Craig Mello for the discovery of RNA interference in C. elegans. The 2008 Nobel Prize in Chemistry was awarded to Marty Chalfie for his use of C. elegans to develop in vivo GFP applications.
Our lab is interested in understanding the role of chemistry in the behavior of nematodes. C. elegans is our primary species, because it is experimentally tractable, and the extensive knowledge base provides a rich context to interpret our new chemical data. We also use C. elegans as a model system to develop new metabolomics technologies, and we are launching a major project to associate the C. elegans metabolome with is genome and phenome. We have a great interest in applying what we learn from C. elegans to other nematodes, especially parasites.