Mapping of the mouse Rxr loci encoding nuclear retinoid X receptors RXRα, RXRβ, and RXRγ

Recently, a novel subgroup of nuclear hormone receptors called RXRs implicated for retinoid-mediated gene regulation have been identified. RXRs appear to interact with many other nuclear hormone receptors and modulate their functions. We have mapped genetic loci Rxra, Rxrb, and Rxrg encoding three RXR subtypes, RXRα, RXRβ, and RXRγ, respectively, using interspecific backcross mice. None of the Rxr loci cosegregated with each other or with the retinoic acid receptor loci (Rar) mapped previously. Rxra mapped to Chr 2 near the centromere, Rxrb mapped to the H-2 region of Chr 17, and Rxrg was tightly linked to the Pbx gene on distal Chr 1. These results underscore that RXR genes are dispersed in the genome.