Caenorhabditis elegans Resources

Introduction

I created this page as part of my involvement in the Science Education Partnership program at Fred Hutchinson Cancer Research Center. Every summer, nearly two dozen teachers are invited to FHCRC for an intensive 13-day session. Nearly half of the session is spent in the SEP Teaching Lab, where teachers practice basic techniques in molecular biology (i.e. pipetting, PCR, gel electrophoresis, etc.) and learn about resources available to biology teachers. Teachers complete a research project under the guidance of a scientist mentor at one of several host sites. In addition to helping teachers with their project, the graduate-student mentors prepare a seminar series on a topic of interest. The following information comes from our seminar series, "Model Organisms."

Any questions, comments, broken links, etc.? Feel free to e-mail me ().

Contents

Online Resources

Background Information and References

"Sydney Brenner"
  • A discussion of Sydney Brenner’s role in establishing C. elegans as a model organism; in his own words.

    • "The Genetics of Caenorhabditis elegans"

  • Mark Blaxter’s introduction to C. elegans

    • WormBook

  • A new resource that includes reviews on all aspects of worm biology, experimental methods, and resources. Written by key researchers in the field, updated regularly, and freely accessible. An excellent source of background materials.

    • "NCBI Bookshelf"

  • A service of the National Library of Medicine (a division of the National Institutes of Health); a number of biology textbooks available online.
  • Scroll down to "C. elegans II" - the 1997 book that contains detailed descriptions and reviews about the worm.

    • "Worm Literature Index"

  • Comprehensive database of research papers that reference C. elegans
  • Includes "Worm Breeder's Gazette" archives - an occasional publication of the worm community, with informal sharing of observations, ideas and projects related to worms

    • "Atlas of C. elegans Anatomy"

  • Still a work in progress, but includes a lot of useful information on worm anatomy, and has some interesting movies, as well.

    • "Other Nematodes: A Guide for C. elegans Researchers"

  • Useful information on parasitic and non-parasitic nematodes

    • "Ask the Scientists"

  • An interview with Dr. Cynthia Kenyon, who uses C. elegans as a model organism to identify genes involved in aging

    • "Drug Testers Think Small . . . Replacing Lab Mice with Worms"

  • An article in the Access Excellence collection that describes how worms are becoming a favorable model for studying the physiological effects of drugs and pharmaceuticals

    • "Worms, Longetivity and Diabetes"

  • An article written by Sean Henahan about the discovery of a longetivity gene in worms, and its implications for human biology (part of the Access Excellence collection)

    • Society for Developmental Biology Education Links

  • Nice collection of educational resources available online for all grade levels. Resources include not only C. elegans but other model systems as well.

    • Ask a C. elegans expert

  • Hosted by NASA, this page features Q&A from C. elegans experts, with emphasis on the "worms in space" research program. What can worms teach us about life in zero-gravity?

    • Worms win the Nobel Prize!!

  • Learn more about why three prominent worm researchers (Sydney Brenner, H. Robert Horvitz and John Sulston) were awarded the 2002 Nobel Prize in Physiology or Medicine.

    • Worms contribute to another Nobel Prize!!

  • Andrew Z. Fire and Craig C. Mello were awarded the Nobel Prize in Physiology or Medicine in 2006, for their research in RNA interference, or gene silencing by double-stranded RNA, in C. elegans.

    Databases and Images

    "Caenorhabditis Genetics Center"
  • This center is the main supplier of worm strains to the C. elegans community. Whenever mutant strains are generated, they are sent to the CGC, where they can then be provided to other researchers and educational institutions upon request.

    • "Wormbase"

  • The primary source of public-access information about C. elegans. Includes detailed descriptions of all known C. elegans gene sequences, genotypes, phenotypes, mutations, etc.

    • "C. elegans movies"

  • A collection of digital videos of diverse phenotypes in wild-type and mutant worms

    • Development of the Nematode Caenorhabditis elegans

  • Online tutorial that takes students through the successive stages in worm development (from the University of Calgary).

    • Caeno-what?

  • A nice introduction to worms from Sam Ward's lab at the University of Arizona. Mouse-over the worm on the left to identify major parts of the worm body.

    • Applications in the Classroom: Lessons and Ideas

    "The Gene Hunters: Scientfic American Frontiers"
  • One lesson plan using worms, developed in collaboration with this PBS series (note: this link will open a PDF file)

    • "Worms are a lot more similar to people than you may think!"

  • A simple-but-effective introduction to the study of homologous genes in different organisms
  • Online exercise that demonstrates how sequence databases (such as GenBank) can be used to compare gene and protein sequences from different organisms

    • "W.O.R.M. Initiative - Wisconsin Outreach Research Modules"

  • Excellent background information on the value of model organisms in teaching, and in the use of C. elegans in particular.
  • "Introduction", "Model Organisms", and "C. elegans" are nice, clear summaries for teachers
  • "This Project" is a series of online modules utilizing actual research data, and designed to help students learn how to interpret and analyze data to answer specific questions. These modules are most suitable for use in AP classes (or by teachers as background information)

    • Worm Classroom

  • A resource for educators who use C. elegans in their teaching. While most of these resources are targeted for undergraduate educators, resources for high school classes are also available.

    • "Worm Breeding for Dummies"

  • An excellent guide to performing crosses and mapping mutations in C. elegans, written by David S. Fay, Dan Starr, Andy Spencer, and Wade Johnson at the University of Wyoming.

    • "Alcohol, C. elegans and You" - Drug Abuse Research Teams (D.A.R.T.)

  • Describes how to set up and test C. elegans for effects of exposure to drugs and alcohol in the classroom. This website describes the DART research projects at Abraham Lincoln High School in San Francisco, CA.

    • "Elegant Embryology"

  • Describes a simple lab that teaches students about early embryo development and cell divisions. Prepared by Carol Bernon, a participant in the 1997 Woodrow Wilson teacher's workshop.

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    C. elegans in the News and Press

    Science . Vol. 282, Number 5396, Dec. 11, 1998.
  • Special issue reporting the completion of the C. elegans genome.
  • Several good review articles - of particular interest is Mark Blaxter's review, "Caenorhabditis elegans Is a Nematode" (pg. 2041-2046).

    • Barry, Dave. "Here's the complete poop on mutant Seattle worms." Seattle Times. Seattle, Wash.; Mar 21, 1994. pg. B4.

  • A somewhat off-beat profile of Dr. Jim Thomas's lab (at the U. Washington), which studies defecation in worms (among other things)

    • Cooke, Robert. "Worm's complex genome unraveled; 'Map' is big step forward for scientists." Seattle Times. Seattle, Wash.; Dec. 11, 1998. Pg. A3.

    Donn, Jeff. "Enzyme that helps extend life is discovered." Seattle Time. Seattle, Wash.; May 13, 1999. Pg. A6.

    Elias, Paul. "Pursuing Healthier Bacon Through Genetic Engineering and Cloning." March 26, 2006. Associated Press. [This article appeared in the Seattle Post-Intelligencer as "Worm DNA gives bacon a heart-healthy boost", March 27, 2006, pg. A5.]

    Grady, Denise. "A Worm's Life: Right Mutation Makes It Long but Very Dull." New York Times. New York; May 21, 1996. pg. C1.

  • Describes the discovery of "clock" genes, which affect life-span (called "clock" genes due to their role in regulating the length of the cell cycle)

    • Huntington, Rebecca. "Tiny worms may offer clues to cures for human diseases." Seattle Times. Seattle, Wash.; Jul 25, 1999. pg. B3.

  • Profile of Bruce Bowerman, a C. elegans researcher at U. Oregon, who was once a post-doctoral fellow in Jim Priess's lab at Fred Hutchinson Cancer Research Center

    • Steenhuysen, Julie. "Genes switch altered sex orientation of worms." Reuters. Published online Oct 26, 2007. A comment on this article by Dr. Jamie White, one of authors of the study described in the article is a very clear and interesting "behind-the-scenes" look at the process of doing research.

    Sulston, John and Georgina Ferry. The Common Thread: A Story of Science, Politics, Ethics, and the Human Genome". Joseph Henry Press, 2002. This book provides Sulston's account of the development of the Human Genome Project, starting from the C. elegans sequencing project.

    Wade, Nicholas. "The Four-Letter Alphabet That Spells Life." New York Times. New York, N.Y.; Jul 2, 2000. pg 4.4.

  • Describes research at UCSF demonstrating that a single gene controls both social and solitary feeding in worms

    • Wade, Nicholas. "An Adroit Director Of an Unwieldy Team." New York Times. New York, N.Y.; Jun 27, 2000. pg. F.3.

  • Short biographical information on the key players in the worm genome sequencing project

    • Wade, Nicholas. "Animal's Genetic Program Decoded, in a Science First." New York Times. New York; Dec 11, 1998. pg. A1.

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    Setting Up for Your Worm Lab

    Obtaining worms

     The only commercial source I have found is through the Carolina Science and Math Catalog.

    The Caenorhabditis Genetics Center will provide worm strains and bacteria for a small fee, although exceptions can be made for teachers in secondary schools upon written request (see their website for details). The preferred bacteria for C. elegans is E. coli strain OP-50, which is a slower-growing strain than K-12. The CGC will provide OP-50 upon request. The one caveat is that the CGC is primarily a two-person operation, and orders can sometimes take up to 3 — 4 weeks to process. Therefore, it is necessary to plan ahead and allow plenty of time when ordering through the CGC. (They will not provide agar — so you would still need to buy this through Carolina).

    Obtaining mutants:

    Mutant worms with obvious phenotypes are not only useful in studying Mendelian inheritance or genetic mapping, but they are also just plain cool to look at. Here is a list of the more interesting mutants:

  • dpy-5 and dpy-6: these worms are "dumpy" - very small (some look like mini-footballs). These are excellent for genetic studies (such as studying Mendelian inheritance or mapping a mutant) since they’re located on separate chromosomes, and have distinct phenotypes.
  • rol-6: these mutants are "rollers" — because of a defect in their cuticle, they are constantly rolling around on the plate (they are "right-hand rollers", meaning they roll in a clockwise direction). It is a bit difficult to detect at first, but once the phenotype is recognized, it is very easy to pick out.
  • unc-4: "unc" means "uncoordinated"; these worms are able to move forward, but cannot move backward (this is evident by tapping worms on their heads — wild-type worms will move backward 1 — 3 body lengths in response to head-tapping; unc-4 worms will not).
  • unc-22: these worms are called "twitchers" — they constantly twitch/shake. This phenotype is caused by a mutation in a gene that encodes a fibronectin-type protein, which has been implicated in several human neurological disorders.
  • unc-119: another neurological defect; worms are paralyzed, and small ("dumpy-ish")

    • Handling worms:

    Worms are not terribly fussy about their living conditions, as long as they have a plate of bacteria to eat!

    The wild-type strain of C. elegans is "N2" (these are descendants of a strain originally isolated in Bristol, England, in the 1940s). Worms can be maintained at room temperature. (If you have the ability to control for temperature, such as an incubator, 20°C is the ideal incubation temperature — at this temperature, it takes about 3 days from hatching to adulthood. At 15°C, it takes about twice as long. At 25°C, it is about 1/3 as fast.) A plate of starved-out worms, wrapped in parafilm, will be viable for several months if kept at 15°C.

    Aseptic techniques must be observed at all times! Be careful to minimize the exposure of plates to air, as fungi or airborne microbes can contaiminate a plate.

    To maintain well-fed worms:

    Day 1: Pour plates — heat the Nematode Growth Agar as directed, and pour into 60mm x 15mm plates (about 1/2 full). Allow plates to cool and solidify overnight. (Plates can be prepared up to 1 month ahead of time, and kept at 4°C. Pull plates out the day before needed and warm to room temperature). Prepare E. coli culture as directed.

    Day 2: Seed plates — once plates are at room temperature, add 300 µl of E. coli to the center of the plate. (If you don’t have a micropipetter, you could also use a Pasteur pipette or eye dropper — about 3-4 drops of culture. There should be a pool of liquid in the center of the plate, about half the total diameter of the plate). Be careful not to swirl the plates too much — most of the bacterial should be concentrated in the center, surrounded by a ring of bacteria-free agar. Allow plates to sit overnight at room temperature. Unused plates can be stored at 4°C for up to a month. Be sure to warm plates to room temperatures before placing worms on plate.

    Day 3: Place worms on plate — worms can be transferred in one of two ways:

    a. "Chunking" — using a sterile scapel, cut a small cube out of a plate of worms — about 1cm x 1cm. Cut from an area of the plate where there is a medium density of worms (not too high, not too low). Place the chunk, worm-side down, onto the freshly-seeded plates. Chunking will result in a plate of mixed-stage worms, which is useful for observing the continuum of C. elegans development from embryo to adult.

    b. "Picking" — using a tool called a pick, made out of platinum wire (platinum is used since it cools faster). Picking is used when you want to control for the age of the worm, ensure that all progeny on a plate are from the same hermaphrodite, or to transfer worms from a contaminated plate to a fresh plate.

     Day 4: Continue to check your plates daily. If any plates appear to be "starving out" (most of the bacteria has been eaten), then use the chunking method to transfer worms to a new plate. Save one starved plate as a "stock plate" to use in case you have contaminants, or your N2 strains start displaying weird phenotypes as the result of spontaneous mutations. I try to replace my stock plates every 6-8 weeks.

    How to handle contaminants:

    Fungal: Easiest to handle — if fungi develop on a plate, use a pick to remove worms to a new plate. Transfer worms to new plates for several days, until it is clear that no fungal spores were transferred with the worms. (Save the contaminated plates for your students — they are incredibly cool to look at under a dissecting scope! Be sure to seal the plates in parafilm first, to prevent fungal spores from escaping).

    Bacterial: Sometimes, other bacteria or yeast will colonize a plate. These are easy to detect since they will be a different color than the E. coli. If there are contaminated plates, then there is a concern that worms have ingested the contaminating bacteria, and therefore will contaminate any new plates they are moved to. If you have a stock plate, then toss the contaminated plate (wrapped in parafilm), and chunk out worms from the stock plate. If not, then to remove this contamination, prepare a solution of 50% bleach and 50% 1M NaOH (sodium hydroxide). Place one drop of the bleach solution on the unseeded portion of a fresh plate. Use a pick to transfer several adults from the contaminated plate (the adults should have plenty of eggs in their uterus). The bleach will dissolve the adults (and kill any bacteria). The eggs will hatch normally, since bleach cannot penetrate their egg shell). The next day, transfer the hatched larvae to a fresh plate.

     Getting Help:

    Three labs in Seattle work extensively with C. elegans — Jim Thomas’s lab, in the Dept. of Genome Sciences at the University of Washington, and Jim Priess’s and Mark Roth’s labs at Fred Hutchinson Cancer Research Center. Each lab has at least one grad student who has been involved with the SEP program, and is more than willing to help teachers. The best way to get in touch with these labs is through the SEP program.

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    Suggestions for Using C. elegans in the Classroom

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    This page was created and maintained by in July, 2002. Last updated on 31 Oct 2007.