The dog and rat olfactory receptor repertoires
1 UMR 6061, Génétique et Développement CNRS-Université de Rennes 1, 35043 Rennes Cedex, France
2 IRISA, campus de Beaulieu, 35042 Rennes Cedex, France
3 Broad Institute of MIT and Harvard, Charles Street, Cambridge, MA 02141, USA
4 NIH/NHGRI/50 South Drive, MSC 8000, Bethesda, MD 20892-8000, USA
Genome Biology 2005, 6:R83 doi:10.1186/gb-2005-6-10-r83Published: 28 September 2005
Dogs and rats have a highly developed capability to detect and identify odorant molecules, even at minute concentrations. Previous analyses have shown that the olfactory receptors (ORs) that specifically bind odorant molecules are encoded by the largest gene family sequenced in mammals so far.
We identified five amino acid patterns characteristic of ORs in the recently sequenced boxer dog and brown Norway rat genomes. Using these patterns, we retrieved 1,094 dog genes and 1,493 rat genes from these shotgun sequences. The retrieved sequences constitute the olfactory receptor repertoires of these two animals. Subsets of 20.3% (for the dog) and 19.5% (for the rat) of these genes were annotated as pseudogenes as they had one or several mutations interrupting their open reading frames. We performed phylogenetic studies and organized these two repertoires into classes, families and subfamilies.
We have established a complete or almost complete list of OR genes in the dog and the rat and have compared the sequences of these genes within and between the two species. Our results provide insight into the evolutionary development of these genes and the local amplifications that have led to the specific amplification of many subfamilies. We have also compared the human and rat ORs with the human and mouse OR repertoires.