The genetic map of the domestic cat has been developed as a model for studying both feline analogues of human genetic disease and comparative genome organization of mammals. We present here the results of syntenic mapping of 35 genes based upon concordant occurrence of feline gene homologues with feline chromosomes and previously mapped loci in a panel of 41 rodent x cat somatic cell hybrids. These somatic cell hybrids retain rodent chromosomes and segregate feline chromosomes, but in different combinations in each hybrid cell line. Thirty-three of the 35 new locus assignments extend and reaffirm conserved chromosome segment homologies between the human and cat genomes previously recognized by comparative mapping and zoo-FISH. These results demonstrate the extensive syntenic conservation between the human and feline genomes and extend the feline gene map to include 105 assigned loci.