On April 12th, Dr. Hannah Chapin taught a workshop on the model organism C. elegans. One of the first questions that came up was, “What is a model organism?” Caenorhabditis elegans is a microscopic roundworm and precisely nothing like Tyra Banks, so why the word “model?” Students learned that the term “model” is used in the sense of model planes or model cars, where a miniature and often simplified version of something is used for exploration before working on a higher organism, such as a mouse. Even though C. elegans doesn’t have a brain, it’s used to explore how the nervous system develops and how neural connections affect behavior. And though no worm has ever been observed smoking a cigarette, C. elegans has also been used to explore aspects of nicotine addiction.
Hannah alternated presentations on C. elegans development, anatomy, and genetics with opportunities to get to know the worms. Slides with anesthetized worms illustrated the effect of temperature on development. We also got to look at worms crawling on plates and chowing down on bacteria using microscopes in the lab. Along with the normal worms, we also looked at some mutant worms with stumpy bodies and strange locomotion. Knowing the DNA mutation they carried, these C. elegans mutants illustrated the link between genotype and phenotype that Hannah taught in the workshop.
The science of these model organisms has moved far beyond mere characterization. They are used for mapping the location of mutations on a chromosome, and are used to determine whether a given worm carries a particular genetic construct. This brought us to Hannah’s research.
Hannah studies autophagy (from the Greek for self-eating), a combination a trash-removal and recycling system in the cell. After introducing one of the techniques she uses, Hannah showed some of her data. The class participated in a discussion of what could be inferred from the images. Hannah provided hints, as well as background on why the results were significant or unexpected. It was an interesting peek into the lab, and a rare opportunity to see unpublished data.
The class ended with some time for questions and answers. As is so often the case in science, sometimes the answer was simply, “That’s a great question. We don’t know that yet.” Though not as complex as higher organisms, there is still a great deal we don’t know about the tiny roundworm, C. elegans, and it will probably keep Dr. Hannah Chapin and other researchers busy for years to come.
If you missed the class and want to learn about C. elegans, Jove.com has a video introduction. If you want to dive in and learn more, there are a number of sites full of information on C. elegans, including WormBook.org, an open-source textbook.
Photos and Correspondence by Christine Lloyd and Sara Hayden