1. C. elegans as a model organism
Kavya Leo Vakkayil
, BS-MS
IISER PUNE
2/3/2018
Kavya Leo

2. GROWTH OF A RESEARCH AREA
Jonathan Hodgkin, University of Oxford
2/3/2018
Kavya Leo

3. 1. An introduction to C. elegans Anatomy Life cycle
2. A short history of C. elegans research
3. Advantages and applications of C. elegans
4. C. elegans in PUNE
2/3/2018
Kavya Leo

4. C. elegans Small, free living(non-parasitic)soil nematode
Survives by feeding on bacteria
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Kavya Leo

5. C. elegans TWO SEXES: A self fertilizing hermaphrodite(XX) A male(X0)
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Kavya Leo

6. ADULT ANATOMY 2/3/2018 Kavya Leo
A. DIC image of an adult hermaphrodite, left lateral side. Scale bar 0.1 mm. B. Schematic drawing of anatomical structures
A. Schematic drawing of anatomical structures, left lateral side. B. DIC image of an adult male, left lateral side. Scale bar 0.1 mm
C. The unilobed distal gonad of the animal in B is shown as enlarged. D. The adult male tail, ventral view. (Arrow) Cloaca; (arrowhead) fan. Rays 1-9 are labeled with asterisks on the right side.
E. L3 tail, bottom, starting to bulge.
2/3/2018
Kavya Leo

7. LIFE CYCLE
2/3/2018
Kavya Leo

8. A SHORT HISTORY OF C. elegans RESEARCH
Developed by Sydney Brenner(1963).
Mutants published by Brenner(1974).
Post embryonic cell lineages determined (Sulston and Horwitz,1976).
Programmed cell death( Horwitz, 1982).
Complete embryonic cell lineages determined( Deppe et al, Sulston 1983).
Complete connectivity of nervous system was established(1986).
RNAi and miRNA discovered in worms( )(Nobel Prize: Fire, Mello 2006).
First use of GFP in animals(1994) (Nobel Prize: Chalfie, 2008).
First animal whose whole genome was sequenced(97Mb,now 100.3Mb).
2/3/2018
Kavya Leo

9. A SHORT HISTORY OF C. elegans RESEARCH
2/3/2018
Kavya Leo

10. ADVANTAGES OF C. elegans AS A RESEARCH TOOL
Simple
Easy to grow
Short life cycle
Powerful genetic studies can be conducted(Both self fertile and cross fertile)
Transparent
Small
Invariant cell lineage
Fully described anatomy and development
Completely sequenced genome
Tools like RNAi knockdowns can be performed
Stocks can be frozen and preserved
No expensive animal house costs, CHEAP TO MAINTAIN!
Present no biohazard
Large size of progeny
2/3/2018
Kavya Leo

11. APPLICATIONS IN VARIOUS BIOLOGICAL RESEARCH AREAS
1. Developmental biology and Cell biology
Transparency helps to view anatomy and development.
Individual cell lineages can be easily traced and directly inspected by
DIC light microscopy.
Programmed cell death can also be visualized.
2/3/2018
Kavya Leo

12. Green fluorescent protein(GFP)* .
Specific cells, cellular architecture can be directly examined using reporters like
Green fluorescent protein(GFP)* .
Ilys genes(lysozyme) exhibit distinct patterns of pharyngeal
expression.
*GFP= GREEN FLUORESCENT PROTEIN .Small protein derived from luminous jelly fish and can
be introduced as a transgenic tag to mark any protein in the animal.
Jonathan Hodgkin, University of Oxford
2/3/2018
Kavya Leo

13. Act as a model for neuronal development and function.
2. Neurobiology
Act as a model for neuronal development and function.
No brain per say, but have sophisticated nervous system(302neurons/959 cells).
C. elegans responds to chemo attractants/repellants.
Laser beams(selective cutting of neurons) and electrophysiology studies can
be conducted.
Connectome (the complete wiring diagram) have been established.
3. Aging
Short life span helps to conduct genetic screens to find longevity genes.
4. Human disease studies
~75% of human disease genes have potential C. elegans homologs.
~40-50% have a C. elegans ortholog.
2/3/2018
Kavya Leo

14. C. elegans RESEARCH IN IISER PUNE
Biochemical and genetic characterization of chromatin organizer protein Dve-1 and its role in C. elegans development and aging.
The present study seeks to elucidate the mechanism by which chromatin organization impacts organismal aging by studying C. elegans protein (Defective proventriculus) Dve-1.
Identify genetic and physical interactors of C. elegans Dve1.
Generate C. elegans strains mutated in Dve1 and characterize the function of Dve1 during C. elegans development and aging.
2/3/2018
Kavya Leo

15. THANK YOU
2/3/2018
Kavya Leo