Transcript Nobel Prizes for C. elegans!

Introduction of C. elegans
——A model organism
Xiaoqi Sang
2011.6.10
Contents
A Short History
Characters of C.elegans
Applications of C. elegans
Nobel Prizes for C. elegans
C. elegans and Apoptosis
Page
2
Brief Introduction
whole name：Caenorhabditis elegans
Free-living, non-parasitic, transparent，
about 1 mm in length，lives in
temperate soil environments
Research into the molecular begun in
1974
Extensively used as a model organism
Page
3
A Short History
 In 1963, Sydney Brenner
introduced C. elegans as a
model organism for pursuing
research in developmental
biology and neurology
 In 1974, Brenner founded
that EMS can induction
specificity gene mutation of
C. elegans
 Now is widely used in
laboratory research
Page
4
Characters of C. elegans
 small (about 1 mm in length)
 Feeds on bacteria
 Easily to housed and cultivated in large numbers
 Transparent
 Easily to manipulation and observation
 Life cycle is short
 Have 1090 somatic cells at most
 Easily to mutagism
 Can be long-term storage
 Genome is completely sequenced
Page
5
C. elegans
Page
6
C. elegans
Page
7
Life Cycle
 From egg to egg
takes about 3 days
Life span is
around 2 to 3 weeks
under suitable
living condition
Once lay
approximately 3001000 eggs
Page
8
Life Cycle
Page
9
Genome
 The genome was completely sequenced in 1998, It is
the first multicellular-organism (animal) that has a
completely sequenced genome
 The genome size of C. elegans is about a hundred
million base pairs
 Five pairs of autosomes and one pair of sex
chromosome
 Contains approximately 20,100 protein-coding genes
 Contain more than 16,000 RNA genes
Page
10
Sexual determination
 C. elegans has two sexes: hermaphrodites and
males
 In nature, hermaphrodites are the most common sex,
just 0.05% is males
 Hermaphrodites can self-fertilize or mate with males
but cannot fertilize each other
 sex determined by the ratio of sex chromosome
Page
11
XX
hermaphrodite
XO
male
Applications of C. elegans
 Cellular differentiation
 Nervous system
 Embryo development
 Cell cycle
 Meiosis
 Fertilization
 Cleavage
 Fat metabolize
 RNA Interference (RNAi)
 Study and memory
 Aging
 Apoptosis
Page
12
Nobel Prizes for C. elegans!
 The first C. elegans Nobel Prize——The Nobel Prize in
Physiology or Medicine 2002
For the dicovery of Apoptosis
To Sydney Brenner, H. Robert Horvitz and John E. Sulston
 A second C. elegans Nobel Prize——The Nobel Prize in
Physiology or Medicine 2006
For the discovery of RNA interference - gene silencing by
double-stranded RNA
To Andrew Z. Fire and Craig C. Mello
 A third C. elegans Nobel Prize——The Nobel Prize in Chemistry
2008
For the discovery and development of the green fluorescent
protein
To Osamu Shimomura, Martin Chalfie and Roger Y. Tsien
Page
13
C. elegans and Apoptosis
 C. elegans hermaphrodites have 1090
somatic cells
 Mature C. elegans remains 959 cells
 131 cells commit suicide by apoptosis
 116 of the 131 dying cells are cells of the
nervous system and other ectoderm
Page
14
To be continue
15