Primate evolution of an olfactory receptor cluster: diversification by gene conversion and recent emergence of pseudogenes.

Bibliographic Collection: 
MOCA Reference, APE
Publication Type: Journal Article
Authors: Sharon, D; Glusman, G; Pilpel, Y; Khen, M; Gruetzner, F; Haaf, T; Lancet, D
Year of Publication: 1999
Journal: Genomics
Volume: 61
Issue: 1
Pagination: 24-36
Date Published: 10/1999
Publication Language: eng
ISSN: 0888-7543
Keywords: Animals, Base Sequence, Chromosomes, Human, Pair 17, DNA, Evolution, Molecular, Gene Conversion, Humans, In Situ Hybridization, Fluorescence, Molecular Sequence Data, Multigene Family, Primates, Pseudogenes, Receptors, Odorant

The olfactory receptor (OR) subgenome harbors the largest known gene family in mammals, disposed in clusters on numerous chromosomes. We have carried out a comparative evolutionary analysis of the best characterized genomic OR gene cluster, on human chromosome 17p13. Fifteen orthologs from chimpanzee (localized to chromosome 19p15), as well as key OR counterparts from other primates, have been identified and sequenced. Comparison among orthologs and paralogs revealed a multiplicity of gene conversion events, which occurred exclusively within OR subfamilies. These appear to lead to segment shuffling in the odorant binding site, an evolutionary process reminiscent of somatic combinatorial diversification in the immune system. We also demonstrate that the functional mammalian OR repertoire has undergone a rapid decline in the past 10 million years: while for the common ancestor of all great apes an intact OR cluster is inferred, in present-day humans and great apes the cluster includes nearly 40% pseudogenes.

DOI: 10.1006/geno.1999.5900
Alternate Journal: Genomics
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