1. Caenorhabditis elegans
Quite a nifty li’l worm.

2. The Basics
C. elegans is a small worm one millimeter long. There are two sexes, a male and a self fertilizing hermaphrodite. Its inner workings are similar to a human’s, which is part of the reason its considered a model organism.
Widely studied, C. elegans is a popular test subject among neurology researchers and has had many papers published on it in an array of of topics. Currently there are 342 papers listed under PubMed for C. elegans.

3. Who sequenced it? The Sanger Institute and Washington University.
When? While research on C. elegans began 1968 by Sydney Brenner, its genome wasn’t published until and not fully complete until 2002.
Why? Research began on C. elegans because of interest its nervous and developmental systems, as they are very similar to humans. It is still being used in research for these same reasons.

4. Because C. elegans is a eukaryote it contains a nucleus
Because C. elegans is a eukaryote it contains a nucleus. Within that nucleus are 6 chromosomes that contain a total of 100,000,000 base pairs with roughly 19,800 genes.
A related organism, C. briggsae, is in the process of being sequenced. These two are often compared to each other for reference.

5. Ribonucleic acid (RNA)
RNA vs. DNA
RNA-world hypothesis

6. RNA species -messenger RNA (mRNA) -transfer RNA (tRNA)
-ribosomal RNA (rRNA)
-catalytic RNA (ribozymes)
-small interfering RNA (siRNA)
-ncRNAs (miRNA, tncRNA,piRNA...)
rRNA

7. Gene silencing by dsRNA
unc-22 dsRNA
progeny of injected worm
control

8. RNA interference (RNAi)
The Nobel Prize in Physiology or Medizine 2006 for Craig Mello and Andrew Fire for their discovery of RNAi in C.elegans
nobelprize.org

9. RNAi mechanism in C.elegans: basic scheme
less mRNA, less protein = gene silencing

10. RNAi
conserved mechanism (at least (=thousand billion) years old)
roles
primitive immune system
gene regulatory mechanism (via mRNA destruction)
chromatin remodelling (via histone modifications)
DNA elimination (in Tetrahymena thermophila)
tool
functional genomics
potential for pharmaceuticals