For centuries, scientists have used model organisms from the three domains of life, bacteria, archaea, and eukaryotes, to understand biological functions. For example, the bacterium Escherichia coli (E. coli), which has been studied for more than 60 years, has provided important findings in the areas of biological engineering and industrial microbiology. On the other hand, eukaryotic domain organisms like the fly Drosophila melanogaster (D. melanogaster) and the roundworm Caenorhabditis elegans (C. elegans) have been widely used to study genetics and developmental biology. C. elegans was first established as a model organism in 1963 when Sydney Brenner proposed using the simple worms for studies on neuron development. For his work Dr. Brenner was awarded the 2002 Nobel Prize in Physiology or Medicine. Many research labs around the word have continued to work with C. elegans on numerous biological questions, including disease and learning.
How is it possible that a tiny worm can make so many giant contributions to science? It turns out that C. elegans have a number of huge advantages in the lab:
- Complete genome: The C. elegans genome is completed sequenced. Although the genome is simple, containing 30 times fewer nucleotides than humans, almost 40% of the genes are homologous. Since the genome is fully sequenced a lot of information about its genes is available for everyone to use.
- Safety: C. elegans is a non-parasitic soil nematode and can be safely used in the laboratory.
- Space: This worm is small (about 1 mm in length), and does not need a lot space to be cultured. Your students will just need some petri dishes and a box to incubate them.
- Cost: C. elegans feed on bacteria, specifically the E.coli OP50, and can be cheaply cultivated in large numbers (10,000 worms/petri dish) in the laboratory.
- Time: The worms can be found in one of two possible sexes, hermaphrodites (99.9% of worms) and males (0.1%). C. elegans is an extremely fertile hermaphrodite can produce about 300 to 350 offspring under self-fertilization and more if it mates with males. In addition, C. elegans has a short life cycle, development from egg to egg takes only 3.5 days.
Now that you know the convenience of working with C.elegans, why you don’t try experimenting with the worms in your own classroom? We think they’ll really inspire your students to explore the science and techniques behind model organisms.
- Experiment 851 – The Effect of Alcohol on Caenorhabditis elegans: The objective of this experiment is to observe and record the effects of alcohol on normal and alcohol mutant strains of these nematodes.
- Experiment 852 – Chemotaxis: The Science of Attraction: In this experiment your students can observe and record the phenomenon of chemotaxis in normal and mutant strains of C.elegans. Students will examine nematode movement in response to specific chemicals in the environment.
- Experiment 856- Environmental Toxicity Response in C. elegans: The objectives of this experiment are to observe and compare the effects of heavy metals on the environment. Students will learn about heavy metal toxicity by examining the effects of pollutants on both normal and mutant strains of C. elegans.
- Experiment 858-Lighting Up Life: Expression of GFP in C. elegans: This experiment explores molecular methods used by scientists to create and identify transgenic animals. Students will use fluorescent microscopy and PCR to analyze C. elegans that have been engineered to express the Green Fluorescent Protein.
Interested in learning more about using worms in your classroom? Be sure to watch our series of Instructional Videos before performing the experiment. We also have a convenient troubleshooting guide to make your experience as simple as possible.