LOCALIZATION OF THE CHINESE-HAMSTER CAD GENE REVEALS HOMOLOGY BETWEEN HUMAN CHROMOSOME-2P AND CHINESE-HAMSTER 7Q

The trifunctional enzyme CAD catalyzes the first three steps of pyrimidine biosynthesis. By using fluorescence in situ hybridization we have localized the Chinese hamster CAD gene on chromosome 7q11-q13 of diploid fibroblasts. Other genes previously assigned to chromosome 7 include acid phosphatase-1, the M2 subunit of ribonucleotide reductase and ornithine decarboxylase. These genes are also syntenic with CAD on human chromosome 2p. We have then mapped CAD on the pericentromeric region of two different rearranged chromosomes (Z8p and R2q) in a cell line derived from Chinese hamster ovary. The presence of CAD on Z8 and R2 indicates that they derive from rearrangements involving chromosome 7. © 1993 by Academic Press, Inc.