Let’s explore the world of Caenorhabditis elegans, a species of worm commonly using in biological research. These tiny worms first showed up in labs in the late 18th and early 19th century and have since become integral parts of genetics studies.1
These aren’t the type of worms you’d find outside after a rainstorm, though they do prefer humid climates. C. elegans often live in the soil and feed on rotting plant material, so they’re no threat to humans. They are not the type of worms that are parasitic or infectious, so don’t worry!1
Tell me a little more about C. elegans.
C. elegans was characterized by French scientist Emile Maupas, a librarian who studied biology as a hobby.2
Maupas reported the organism’s life cycle as well as its methods of reproduction. The worm grows from a tiny egg into a 1-millimeter long adult within a span of 3 days, making it an ideal specimen for developmental experiments.3 They are extremely easy to grow since they are so tiny. Researchers often keep them in petri dishes!4
What else do we know about worm development?
Quite a lot, in fact! Every cell in the body of the worm has been cataloged and categorized, which is more than we can say for humans. Worms are much more simple organisms, with only 959 somatic cells in the adults.5
Why would I use C. elegans for studying human biology?
Like with fruit flies, worms can tell us a lot about how genes interact and what they normally do. For example, worms have almost the same number of protein-coding genes as humans, somewhere around 20,000.3 While these genes aren’t all the same as those in humans, many have conserved functions. Sydney Brenner won a Nobel Prize with Horvitz and Sulston for his work describing the unc set of muscle genes in worms; his Nobel lecture was an ode to C. elegans entitled “Nature’s Gift to Science.”6 This Nobel work cemented nematodes as one of the most popular model systems in genetics research today.
I spoke with Coleen Murphy, a professor of Molecular Biology at Princeton University, about her research with C. elegans. She uses worms to study aging and age-associated diseases, like Alzheimer’s Disease, Parkinson’s Disease, or dementia.
Why did you first decide to use C. elegans as your lab’s model organism of choice?
CM: “I had started using C. elegans to study aging while doing my postdoc in Cynthia Kenyon’s lab – her work showed that worms are great for aging research because they grow and age fast (they live for only 2-3 weeks), and the genetic tools in worms are powerful. Because they have a few major tissues, the question of non-autonomous determination of lifespan can be addressed well. And as we found in my lab, worms can be used to model both reproductive aging and cognitive decline with age, so they are a really nice and fast system to identify conserved regulators of longevity and age-related decline.”
How do you translate discoveries from worms (with such short lifespans) into findings for humans (who live long lives)?
CM: “Most of the pathways determine relative rates of aging within species, and those pathways (for example, insulin signaling and dietary restriction) seem to be shared across species. Other than our example of male pheromone being used by hermaphrodites to kill males in androdioecious (a reproductive system that combines both male and hermaphrodite) species, I can’t think of another pathway that affects longevity only in one species (I’m sure there are some, but we generally haven’t studied them).”
What are some secret benefits to being in the C. elegans research community?
CM: “Lately I’ve come to really appreciate the fact that there is a founder effect – Sydney Brenner and Bob Horvitz trained a lot of women in their labs, and those women went on to establish their own labs and are leaders in the worm community. They, in turn, trained a lot of women, and so our field is gender balanced in a way that I think may be rare compared to other fields.”
Thanks for your help, Dr. Murphy! Good luck with your research!
And don’t forget – the worm is just one of many tiny laboratory assistants!
- Frezal L, Felix M. 2015. “The Natural History of Model Organisms: C. elegans outside the Petri dish.” eLife: 4:e05849. Doi: 10.7554/eLife.05849
- Mark Edgley and the Riddle Lab. “What is C. Elegans? What is Caenorhabditis Elegans and why work on it?” University of Minnesota College of Biological Sciences.
- “Caenorhabditis Elegans: Development from the Perspective of the Individual Cell.” Molecular Biology of the Cell. 4th edition. https://www.ncbi.nlm.nih.gov/books/NBK26861/