Allelic variation linked to adenine phosphoribosyltransferase locus in mouse teratocarcinoma cell line and feral-derived mouse strains

Southern blot analysis reveals two distinct adenine phosphoribosyltransferase (APRT)alleles in the P-19 mouse teratocarcinoma cell line. One allele is identical to that observed in common laboratory mouse strains (Mus musculus domesticus).The restriction enzyme site variations between the two alleles occur in sequences located both upstream and downstream of the APRTgene, but not within it. Although the P-19 cell line was established from a C3H strain embryo (Mus musculus domesticus),a sixth generation ancestor of this embryo was a feral mouse (Mus musculus musculus).The restriction pattern of the variant APRTallele in P-19 is identical to that of a feral-derived Mus musculus musculusanimal, establishing the origin of this allele in the P-19 cell line. A third, distinct APRTallele was found in a Mus spretusferal-derived mouse. Exploiting the differences between the two APRTalleles in the P-19 cell line, we have demonstrated their sequential loss in APRT-deficient clones.