Worm-o-ween Series: Welcome to the World of Worms

Welcome to Worm-o-ween! Nothing says spooky like worms in a science laboratory!

For the month of October we are releasing a weekly worm post that should help you on your future worm experiments. This week is all about the basics. What C. elegans are, why we study them and a quick look at their life cycle.

What are C. elegans?

These 1 mm sized nematodes are transparent and are commonly used in scientific experiments. Although soil is the typical worm environment, in laboratories worms are grown and maintained on agar plates full of bacteria. Agar plates covered with E. coli bacteria are vital for healthy growth and maintenance of worms. This spread of bacteria acts as a food source for the nematodes. The presence of food is super important for these worms, without food their growth would be severely stunted and would make it harder to develop past a young larval stage. For the experiments that Edvotek provides, it is important to see worms at various stages of growth, so make sure that ample food is provided for your worms during your experiments.

For Edvotek experiments, the food source used are OP50 Bactobeads. To grow up the bacteria, you can dissolve a few Bactobeads in liquid recovery broth and create a bacterial culture. The agar plates are NGM (nematode growth media) plates. The NGM media comes in a ready pour bottle, and is prepared similarly to how our LB ready pour bottles are made. It is much lighter in color, almost white. You break the agar into chunks by squeezing the bottle, then heat it in the microwave until it completely melts. When cooled you will add NGM salts to finalize the NGM recipe before pouring plates. Use the same aseptic technique you have used in prior experiments to pour these NGM plates. The worms like temperatures around 12°C to 25°C, so room temperature is generally a great option, along with a dry and dark environment! We recommend storing worm plates inside a cardboard box at room temperature. 

Why We Study C. elegans

A model organism is any plant, animal or microorganism that allows us to study fundamental questions in biology that may be hard to study directly in complex organisms like humans. Nematodes started being a prominent model organism in the 70s. They are an attractive model organism because they have a simple genome, a fast generation time, are easy to maintain, and inexpensive to maintain. They are important in studies of embryogenesis, morphogenesis, development, nerve function, behavior, aging and genetics. They have been completely sequenced and many genetic mutants are available to study. 35% of worm genes have human homologs, making many of their genes vital to study human health and development. They have also become big in the neuroscience field as they have an extensive nervous system, with one-third of their somatic cells being comprised of the nervous system.

The Development and Life Cycle of Nematodes

There are four larval stages worms cycle through before reaching adulthood. It takes about 3-5 days for worms to achieve adulthood from an embryo, and they live between 2-3 weeks. On the NGM plates, the worms move, eat, develop, mate and lay eggs during their life cycle. Once eggs are laid on agar, they will hatch after approximately 14 hours. In the next two days the worms will go through the larval stages L1 through L4, getting larger and larger through each stage. When the fourth stage ends, the worms are considered reproductively mature and are capable of egg laying. Adult worms are ideal for a lot of studies and experiments, since their nervous systems are fully developed.

There are two naturally occurring sexes in C. elegans. Most worms are hermaphrodites, meaning they have both male and female reproductive cells. Alone, the hermaphroditic worms can produce about 300 offspring. The hermaphroditic worms do need the free-living male worms present to reproduce in large quantities. These worms together can produce over 1000 offspring in a generation.

Tune in each week for a new worm blog post! Check out our Instagram and Facebook to find the answer to the joke of the week!

October 12th, 2023: Have questions about how to best maintain worms? We have created a comprehensive guide that summarizes all you need to know about worm maintenance in a laboratory.

October 19th, 2023: Have troubleshooting questions about your worm experiment? We have collected our most FAQs about worms in one place!

October 26th, 2023: Wondering what these worms look like under a microscope? We are providing a guide of worm images and resources that will be helpful in your future experiments!

Joke of the Week: What kind of worms make the best carpenters?