Mapping of a rat multidrug resistance gene by fluorescence in situ hybridization.

A cDNA clone encoding the rat mdr1b (Pgy2) gene was recently isolated and characterized. This gene has a high degree of sequence identity with other Pgy genes, particularly the mouse Pgy2 gene. By means of in situ fluorescence hybridization, the rat Pgy gene was localized on chromosome 4 band q12. This regional mapping will facilitate the identification of synteny groups on rat, mouse, and human genomes and chromosomal rearrangements during mammalian evolution.