1. Introduction to C. elegans Ms. Gaynor Honors Genetics http://labs.bio.unc.edu/Goldstein/crawl.mov

2. What is a “nematode”? It is a round worm! – There are other types of worms Flatworms: tapeworms, flukes Segmented (annelids): earthworms

3. Caenorhabditis Elegans (multicellular, eukaryote) Very small round worm-1 mm long! Hermaphrodites (male & female parts) Life span: 2-3 weeks New offspring EVERY 3 days 19,099 genes (small genome) – 40% are equivalent to human genes ~1000 cells Taught us about: – Cell suicide (apoptosis) and cell health, human aging, cancer, neurological disorders, animal development, diabetes http://www.exploratorium.edu/imaging_station/gallery.php?Asset=GFP%20%3Cem%3EC.%20elegans% 3C/em%3E&Group=&Category=%3Ci%3EC.%20elegans%3C/i%3E&Section=Introduction

4. C. elegans- A Perfect Model Organism Model organism for genetic study meets certain criteria: – easy to grow – short life cycle – produce many offspring – relatively inexpensive – Easy to keep/feed – easy to manipulate/mutate “KNOCK OUT” or “TURN OFF” genes then look for consequences

5. C. Elegans Information Habitat – Free living in soil – It’s a NON-PARASITIC round worm Most other round worms are parasitic! Food – Feeds on bacteria (E. coli) in soil – E. coli OP50 is used as nematode food in lab

6. In this lab…E. coli OP50 this strain of bacteria can NOT synthesize (make) uracil Can NOT live in human gut… but still be careful and WEAR GLOVES!!! – No food or drink (or gum) in lab

7. In this lab… C. elegans will come in 3 different phenotypes – WILD TYPE – dpy-11 (“dumpy” mutant) – bli-1 (“blister” mutant) We will use the wild type strain as a control group (comparison) in order to identify the 2 mutants

8. In this lab… you will use agar plates (petri dishes) with bacteria Agar – A yellow colored “jello” made of sugar Agar that worms live on is called NGM-lite – Bacteria live on agar and eat this agar, worms eat bacteria – A plate with bacteria on it is called a “seeded” plate a seeded plate that is ready for use

9. In this lab… “chunking” "Chunking" is a way to keep worms alive and maintain growth – Cut a 1 cm square "chunk" of agar with worms in it from a plate with growing worms Use a sterile scalpel dipped in alcohol and flamed before and after each use – Transfer “chunk” to new seeded plate When to use this technique: – When you don't care exactly how many worms are transferred plate.

10. When chunking, be careful of contamination…use “pac-man” technique!

11. Life Cycle of a C. elegan

12. A typical view of a seeded plate… http://www.dnatube.com/video/5962/Celegans-population

13. Another typical view of a seeded plate… http://www.dnatube.com/video/5961/C-elegans-responding-to-a-touch-stimulus

14. bli-1 mutant

15. dpy-11 mutant