Nematodes

Generalities

The benefits of using Caenorhabditis elegans (C. elegans) as a model organism are diverse. Its development follows a program that is consistent from one individual to another, and is well known. This knowledge is particularly useful for studying the mechanisms of cell differentiation.

Also, the number of cells that die during development is precisely defined, making it easier to study the mechanisms involved in apoptosis. The endogamic nature of C. elegans through self-fertilization and the possibility of crossing hermaphrodites with males offers an advantage previously reserved for the plant reproductive system. Moreover, the strains are easy to breed and maintain over the long term.

C. elegans is also one of the most basic organisms with a nervous system, allowing easy study of this system. Finally, its transparent body facilitates the study of cell development and differentiation, which are similar to that of vertebrates.

Reproduction

Breeding season: all year round.

Lifecycle: at 22°C, approx. 55 hours between egg and adult.

Two sexes: male and hermaphrodite.

Hermaphrodites can reproduce with males or self-fertilize.

Tools

EST library that improved annotation of the genome and the estimation of the efficiency of gene predictions.
ORFeome: All of the Open Reading Frames (ORF) of the genome predicted in silico available in the Worfdb database.
Promoterome: clone library containing the promoters predicted in silico in flexible vectors such as Gateway™ (Invitrogen), which allows the integration of these promoters in other vectors. The clones are available in a specific database.
ORFeome and Promoterome allowed the implementation of a large number of techniques and functional genomic analysis for C. elegans (transcriptome, exact localization of proteins, etc.)
RNAi gene silencing allows large-scale analysis of gene function in C. elegans. All RNAi phenotypes are available to researchers on the public Wormbase library.
The C. elegans Knockout Consortium is conducting gene silencing analyses by deleting alleles of certain target genes.
Expression profiles obtained through genetically modified organisms with promoter::GFP or promoter::ORF::GFP constructs.
The Genome Science Center provides researchers with an expression profiles library obtained from the promoter construction::GFP
The mapping of protein-protein interactions has been carried out using the "double hybrid" system as part of the Interactome Mapping Project. The data are grouped in the Worm Interaction Sequences Tags database.
Several studies investigated gene expression by RNAseq with single cell resolution (e.g. http://atlas.gs.washington.edu/worm-rna/).