CHROMOSOMAL LOCALIZATION OF THE HUMAN AND RAT GENES (PDE4D AND PDE4B)ENCODING THE CAMP-SPECIFIC PHOSPHODIESTERASE-3 AND PHOSPHODIESTERASE-4

Through the use of somatic cell hybrids segregating either human or ra t chromosomes, we determined the chromosome localizations of two genes encoding cAMP-specific phosphodiesterases (cAMP-PDEs). PDE4D, the gen e encoding the cAMP-PDE isoform 3 (IVd), was assigned to human chromos ome 5 and rat chromosome 2, and PDE4B, the gene encoding the cAMP-PDE isoform 4 (IVb), was assigned to human chromosome 1 and rat chromosome 5. These localizations extend the homology between rat chromosome 2 a nd human chromosome 5, on the one hand, and between rat chromosome 5 a nd human chromosome 1, on the other hand.