International Mammalian Genome Society

The 15th International Mouse Genome Conference (2001)

Table of Contents * Complex Genetics * Developmental Genetics * Gene Annotation * Gene Discovery * Genome Sequencing * Functional Genomics * Mutagenesis * Presentations * Verne Chapman Memorial Lecture

Dr Claire Amadou
CNRS, UPR2163
Chu Purpan
Toulouse 31300 France

Co-Author: 1)Younger RM, 2)Fischer Lindahl K, 1)Beck S
Institutions: 1)The Sanger Centre, 2)Howard Hughes Medical Institute, University of Texas Southwestern Medical Center

Olfactory receptors (OR) are encoded by a huge number of genes grouped in clusters, which are spread all over the genome. OR genes have been identified in many species and display disparate similarity in sequence. OR genes are therefore expected to harbor clues about the dynamics and evolution of the genomes. We have cloned and are sequencing a 1 Mb cluster of OR genes, which is located at the distal end of the Major Histocompatibility Complex (MHC) and is orthologous between man and mouse. We will present a summary of the information obtained so far by analysis of the sequence and comparison with the human cluster:

1. at least one gene has a clear ortholog,
2. the genes have evolved independently in the two species
3. the mouse has duplicated more ORs than man, or more copies of the duplicated ORs have been maintained in the mouse genome since the mouse-human divergence,
4. several genes seem to have no ortholog in the other species within the cluster. If this is confirmed after further sequencing and analysis, it suggests that unique OR genes have evolved after the divergence of the species, or have been deleted in one species.

• Ehlers et al. (2000) MHC-linked olfactory receptor loci exhibit polymorphism and contribute to extended HLA/OR-haplotypes. Genome Res. 10:1968-1978.
• Younger et al. (2001) Characterization of clustered MHC-linked olfactory receptor genes in human and mouse. Genome Res. 11:519-30.