Sequence analysis in the olfactory receptor gene cluster on human chromosome 17: recombinatorial events affecting receptor diversity.
A cosmid clone covering a region of high olfactory receptor (OR) gene density inside the OR gene cluster on human chromosome 17 (17p13.3) was subjected to shotgun automated DNA sequencing. The resulting 40-kb sequence revealed three known OR coding regions, as well as a new OR pseudogene (OR17-25), fused to one of the previously identified OR genes (OR17-24). The suggested mechanism for the generation of this doublet structure involves an initial duplication mediated by flanking repeats and a subsequent deletion via nonhomologous recombination. Sequence analysis further suggests that the two other OR genes present in the cosmid (OR17-40 and OR17-228) may have evolved by ancient tandem duplication of an 11-kb fragment, mediated by recombination between mammalian-wide interspersed repeats. The duplicated genes appear to be complete and potentially functional. Their conserved structure reveals a long upstream intron and a previously uncharacterized 5' noncoding exon. No additional genes could be discerned in the cosmid, suggesting that the cluster may be part of a dedicated OR subgenome.
Glusman
G
G
Department of Membrane Research and Biophysics, The Weizmann Institute of Science, Rehovot, Israel.
Clifton
S
S
Roe
B
B
Lancet
D
D
D001483:Base Sequence; D002460:Cell Line; D002886:Chromosomes, Human, Pair 17; D003360:Cosmids; D004247:DNA; D014644:Genetic Variation; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D012326:RNA Splicing; D018035:Receptors, Odorant / Q000235:genetics*; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D014158:Transcription, Genetic
D018035:Receptors, Odorant; D004247:DNA