Linkage genetics of mouse ornithine decarboxylase (Odc).

Ornithine decarboxylase (ODC) is synthesized as a single polypeptide in the mouse, but DNA sequences reactive with ODC cDNA probes have been mapped to multiple mouse chromosomes. A DNA fragment from the untranscribed 5' flank of a transcriptionally active ODC gene has been used as a probe to define a restriction fragment length polymorphism associated with the gene. The pattern of inheritance of this polymorphism in recombinant inbred strains of mice and in progeny of a conventional backcross localized it to proximal chromosome 12. This result confirms previous experiments with somatic cell hybrids that mapped the gene to chromosome 12 and further defines the linkage group conserved between proximal chromosome 12 and human chromosome 2p. The other ODC homologs are tentatively identified as cDNA-like pseudogenes.