[
International Worm Meeting,
2003]
We are Abraham Lincoln High School students using C. elegans in an after-school research class with a sufficiently equipped lab. C. elegans is a good model system for us because there are no ethical issues surrounding its use, it is safe, has a short life span, is easy to grow in a small space, doesn't require special facilities, and is cheap! C. elegans was new to us, so we began the year by learning the basics: mixing media pouring plates, culturing bacteria, seeding plates, identifying males and hermaphrodites, staging worms, comparing N2 and mutants, and setting up crosses. In two months, we became skilled at pipetting, microscopy, sterile technique, chunking, and picking worms. After we had acquired basic skills, we learned how to search the literature. To understand abstracts, we learned new vocabulary. In the process of researching previous work we developed our own questions, and each of us wrote a research proposal. We then merged our ideas and formed two research teams. One team grew C. elegans on Bacillus subtilis, and the other tested the ability of hermaphrodites and males to negotiate a maze. The B. subtilis team first asked whether worms would survive on the thick, malodorous lawn. We then asked if there would be morphological, life cycle, or chemotaxis differences between worms fed B. subtilis and worms fed E. coli. Our data indicated that worms grew on B. subtilis and that, after many generations, they progressed normally through development and continued to show normal morphology. We are continuing to look for sensory disparity using a chemotaxis assay with benzaldehyde or diacetyl as the attractant. The maze team designed a maze using copper to repel worms. We are collecting data comparing the ability of E. coli-fed hermaphrodites versus males to negotiate our maze. We would like to expand the study to include assays with B. subtilis-fed worms. Worm research has gone well at Abraham Lincoln High School. We have asked our own questions, and designed and conducted our own experiments to find answers. We highly recommend that other high schools work with C. elegans. To be successful, the schools need equipment to culture worms, funding for disposable materials, dedicated teachers, and motivated students willing to spend time to do scientific research. The assistance of a scientist with knowledge about C. elegans is also helpful.
[
International Worm Meeting,
2005]
Microbacterium nematophilum is a bacterial pathogen of C. elegans (Hodgkin et al, 2000) that adheres to the rectum and post-anal region of the worm causing swelling of the underlying hypodermal tissue, mild constipation and slow growth rates. Affected worms are described as having a Dar (Deformed Anal Region) phenotype. C. elegans responds to this infection in part through activation of an ERK MAP kinase cascade which mediates tail swelling and prevents severe constipation (Nicholas and Hodgkin, 2004). To identify the downstream transcriptional changes that occur in C. elegans during this host/pathogen interaction we have conducted a genome wide analysis of gene expression using Affymetrix gene chips. We infected a synchronised population of larval C. elegans in liquid culture for 6hrs before harvesting the worms and extracting RNA. Our control sample was an identical experiment using an avirulent M. nematophilum generated in our laboratory by Tanya Akimkina and Steve Curnock. Analysis of data from triplicate microarray experiments has identified a number of statistically significant gene clusters whose expression changes upon infection. Clusters containing up-regulated genes are located on chromosomes IV and V and include C-type lectins, lysozyme-like proteins and proteins containing metridin-like ShK toxin and DUF141 domains. An RNAi feeding screen of these and other induced genes has identified a number that affect the Dar response. The microarray data suggest that although similar functional domains are found in proteins induced by both M. nematophilum and other pathogens, the response of C. elegans to M. nematophilum is specific. Hodgkin, J. Kuwabara, P. E. Corneliussen, B. Current Biology 200010 ;1615-1618 Nicholas, HR, Hodgkin, J. Current Biology 2004 14 ;1256-1261