Transcript Caenorhabditis elegans - Clayton State University

Caenorhabditis elegans
(C. elegans)
Kathy Szeniawski
Clayton State University
Spring 2008
Alternate Food Sources
Population Growth
& Behaviors
C. elegans
Non Parasitic
 “Bacteria Eating”
Nematode
 959 Somatic Cells
 Hermaphrodites
and Males
 Egg/Embryonic
Stage
 L1-L4 molts
 ? Dauer Stage
(Hibernation)
 Adult
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Kathy Szeniawski
C. elegans Natural Habitat
Nutrient and
Microorganism rich
organic material
 Cultures obtained
from compost/garden
soil, rotting fruit and
mushroom beds
 Associated with
millipedes, insects,
snails and slugs
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Photoblog.com
Queensbury net
Paintworks
Why C. elegans?
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Feeds on OP-50 E. coli
Bacteria in the lab
 Short Life Cycle/Can
produce several
generations in a short
period of time
 Perfect for Genetic
Research
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Kathy Szeniawski
Easy/Inexpensive To
Maintain
Lives in a Petri Dish
Can be easily mutated
OP-50
E. coli
Grow OP-50 E. coli
at 37 degrees C
overnight in 2X YTB
(Yeast Tryptone
Broth)
 Pipette onto NGM
agar plates
 Grow your “Bacterial
Lawn” for 2 days
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Kathy Szeniawski
Kathy Szeniawski
Kathy Szeniawski
C. elegans Worm Farming
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Prepare NGM agar plate
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Grow an OP-50 E. coli
lawn
Chunk transfer or Single
worm transfer
Grow at room temp
Extract eggs from Adult
Worms can be frozen
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Kathy Szeniawski
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Kathy Szeniawski
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Kathy Szeniawski
Contamination
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Maintain Sterile Techniques
Kathy Szeniawski
Kathy Szeniawski
Worm Research
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Research papers on “Different food source” experiments
used different strains of bacteria to feed to the worms.
I hypothesized that wild type worms in their natural
environment consumed food items since the lab worms
that were collected were located in compost piles,
mushroom beds and rotten fruit.
N2 wild type (normal) worms used
Transfer worms onto plates containing food products
Observe and document population growth and behavior
What Will the Worms Eat?
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OP-50 Bacteria
Fruit Snacks
Tofu
Hoodia chews
Trail Mix (Assorted
dried fruits and nuts)
Spinach
Mushrooms
Project: 10 Plates of Each
Spinach
 Mushroom
 Tofu
 Bacteria
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Population Designation (0-5)
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+
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Swarm +++++
Few on Surface
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Several on Surface
Results
My Hypothesis is Supported
Population
5
Size
4
Bacteria
3
Tofu
2
Spinach
Mushroom
1
0
1
2
3
6
7
8
9
10
13
15
Days
All Populations Survived
Results
Population
5
Size
4
Bacteria
3
Tofu
2
Spinach
Mushroom
1
0
1
2
3
6
7
8
Days
9
10
13
15
Spinach
5
T test Day 8
p values
B/T= 9.915x10-6
B/S = 0.017
B/M = 7.77x10-6
T test Day 15
p values
B/T = 0.020
B/S = 1
B/M = 1.62x10-6
Size
4
3
Bacteria
2
Spinach
1
0
1
2
3
6
7
8
9
10
13
15
Days
Bacteria and Spinach do not support population growth as well as Tofu and Mushrooms
Mushrooms
5
5
4
4
3
Bacteria
2
Tofu
Size
Size
Tofu
3
Bacteria
2
Mushroom
1
1
0
0
1
2
3
6
7
8
Days
9
10
13
15
1
2
3
6
7
8
Days
9
10
13
15
Unusual Behaviors Observed
Worms eating food products
 Egg laying balls of Hermaphrodites
 Egg mounds visible to the naked eye
 Larval worm balls
 Larval worms participating in Cannibalism
 Larval worms killing and eating dust mites
 Vortexes in food
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Egg Mounds, Worm Balls &
Vortexes
Future Research
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Repeat experiment with controlled
seeding
Use equal masses of food products on all
plates
Collect statistical data every day
– Population size
– Amounts of Large worms vs. Small worms
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Observe behavior
Conclusion
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Different food sources CAN sustain
C. elegans
Cannibalistic behavior observed several times;
Only larval worms observed participating in
cannibalism
 Larval worms observed killing/eating dust mites
 Overall Population size quickly spikes, then
tapers off until only a few Dauer worms exist
 Worm size in population tapers off to all small
worms at the end of the growth curve
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Thank-You
Dr. Francine Norflus, Research Mentor
 Dr. Michelle Furlong
 Larry and MaryEllen Szeniawski
 Kheem Tan
 Clayton State University Faculty and Staff
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References
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Altn, Z.F. and Hall, D.H. 2005. Handbook of C. Elegans Anatomy.
Introduction to C. Elegans Anatomy. In WormAtlas.
http://www.wormatlas.ord/handbook.contents.htm
Kiontke, Karin. and Sudhaus, Walter. Ecology of Caenorhabditis
species. (January 09, 2006), Wormbook, ed. The C. Elegans
research community, Wormbook, doi/10.1895/wormbook.1.37.1,
http://www.wormbook.org
Brenner, Sydney. The worm goes to school. 2003. Institute of
Molecular and Cell Biology and National Institute of Education
Barriere, Antoine. And Felix, Marie-Anne. Isolation of C. Elegans
and related nematodes. (July 17, 2006), Wormbook, ed. The C.
Elegans research community, WormBook,
doi/10.1895/wormbool.1.115.1 http://www.wormbook.org
Shtonda, Boris and Avery, Leon. Dietary choice behavior in
Caenorhabditis elegans. 2006 The Journal of Experimental Biology 209,
89-102.