ORGANIZATION AND EVOLUTION OF OLFACTORY RECEPTOR GENES ON HUMAN-CHROMOSOME-11

Olfactory receptors (OR) are encoded by a large multigene family inclu ding hundreds of members dispersed throughout the human genome. Clonin g and mapping studies have determined that a large proportion of the o lfactory receptor genes are located on human chromosomes 6, 11, and 17 , as well as distributed on other chromosomes. In this paper, we descr ibe and characterize the organization of olfactory receptor genes on h uman chromosome 11 by using degenerate PCR-based probes to screen chro mosome 11-specific and whole genome clone libraries for members of the OR gene family. OR genes were identified by DNA sequencing and then l ocalized to regions of chromosome 11. Physical maps of several gene cl usters were constructed to determine the chromosomal relationships bet ween various members of the family. This work identified 25 new OR gen es located on chromosome 11 in at least seven distinct regions. Three of these regions contain gene clusters that include additional members of this gene family not yet identified by sequencing. Phylogenetic an alysis of the newly described OR genes suggests a mechanism for the ge neration of genetic diversity. (C) 1998 Academic Press.