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Introduction of C. elegans. ——A model organism. Xiaoqi Sang 2011.6.10. Contents. A Short History. 01. C haracter s of C.elegans. 02. Applications of C. elegans. 03. Nobel Prizes for C. elegans. 04. C. elegans and Apoptosis. 05. Brief Introduction.
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Introduction of C.elegans ——A model organism Xiaoqi Sang 2011.6.10
Contents A Short History 01 Characters of C.elegans 02 Applications of C.elegans 03 Nobel Prizes for C. elegans 04 C.elegans and Apoptosis 05
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
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
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 Nice model organism!
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 300-1000 eggs
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
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 • sexdetermined by the ratio of sex chromosome XX hermaphrodite XOmale
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
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
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 thenervous system and other ectoderm