YAC transgene-mediated olfactory receptor gene choice

In the mouse, individual olfactory neurons express one of a thousand distin ct olfactory receptor genes. Furthermore, only one allele of the expressed gene is transcribed, This phenomenon, random allelic inactivation, along wi th the observation that the olfactory receptor genes reside in. large chrom osomal arrays, suggests a role for long-range gene regulation in olfactory receptor gene choice, We have constructed a 300-kb yeast artificial chromos ome (YAC) transgene in which a single receptor gene is marked whine maintai ning its coding region. This 300-kb piece of DNA functions as an independen t olfactory receptor gene locus in directing olfactory receptor gene choice in both the olfactory system and the accessory olfactory system (vomeronas al organ, VNO), Furthermore, the transgene, like endogenous olfactory recep tor loci, is subject to allelic inactivation, (C) 2000 Wiley-Liss, Inc.