C. elegans as a model system

The soil nematode C. elegans has provided fertile ground for the study of developmental biology and it has become an important model system for biomedical research. Among the many features that make the worm a powerful model system is its small size, rapid development, ease of cultivation and cryopreservation. In addition, C. elegans animals have an invariant number of cells whose lineages have been entirely mapped thanks to its transparency.  

Identification of entire cellular pathways has been possible using forward genetic approaches such as chemical mutagenesis screens. C. elegans is a self-fertile organism, but males can arise at a very low frequency. This facilitates the recovery, maintenance and mapping of mutants, and the availability of multiple genetic balancers allows the maintenance of lethal or sterile mutants. Reverse genetics studies are also possible thanks to the ease of RNA interference and more recently, the ability to generate targeted mutations in the worm genome using CRISPR/Cas9 have further expanded the toolbox of genetic tricks available to investigators. 

But perhaps the most important attribute of worms that makes them useful in biomedical research in the conservation of entire genetic pathways. Over 60 percent of mammalian genes have worm homologs. In fact, the worm has played a pivotal role in the genetic dissection of cellular pathways of high medical importance including cancer, Alzheimer's disease and diabetes.  

If you would like to learn more about this tiny but incredible worm, we recommend the following websites:

http://wormbook.org/chapters/www_celegansintro/celegansintro.html
http://www.wormatlas.org/
http://wormclassroom.org/