SciREN lesson plan intro to accompany Mighty Mutant Worms

1. Mighty Mutant Worms

2. Many scientists will spend their entire careers
studying animals like these
So that we can
answer questions like
How we can stop
cancer from
spreading?
How does the brain
work?
Can we regenerate
damaged tissues and
organs?
WHY?

3. Genetics
• How DNA of an organism influences what it
looks like or what it does
Genotype
Phenotype

4. C. elegans
• A species of worms in soil
• Small and transparent
• Grow really fast (about 2 days from egg to adult)
• Self-fertilizing (a single worm will reproduce)
• Can survive starvation and freezing
• First animal to have its genome sequenced
• Simple enough that we know what every cell is
supposed to do

5. Working with worms

6. Studying Cell invasion in worms
(Sherwood, et. al 2005)

7. The Pvl phenotype
Wild type
Pvl (protruding vulva)

8. Screening for mutants
Use a mutagen to induce changes in DNA
2 generations later
Pick worms with the desired
phenotype to a new plate
The mutant worm
reproduces more worms
with the phenotype

9. Screening for mutants
• Now we have mutants, but in order for this
information to be useful we have to
– Figure out which gene is mutated
– Figure out how that mutation is affecting
the invading anchor cell
? ?

10. Help with the screen
• The questions on this handout will take you
through experiments done in a screen using C.
elegans to study cell invasion. Hopefully, we’ll
identify new and interesting genes!

11. More questions to consider
• How can we use the information we learn
about genes that are involved in invasion to
treat diseases like cancer?
• What effect might natural selection have on
mutations that affect cell invasion in worms?