Figure 5.

Loss of heterozygosity by gene conversion or gene deletion. (A) RT-PCR on clonal nodules in a Fah^−/−, Hgd^aku/Hgd^wt mouse. Only 4 of the 10 nodules showed a wild-type-length PCR product (∗). Mutant PCR products with one or two exons deleted (see Fig. 4) were amplified in each nodule. In those nodules that had an amplifiable wild-type allele, sequencing of cloned RT-PCR products showed the same mutation in all clones, confirming that the dissected sections indeed were clonal nodules. (B) PhosphorImager analysis of genotyping assay on liver genomic DNA. Two liver pieces (nonclonal) from three Hgd heterozygous mice were analyzed, as well as two heterozygous controls in which the wild-type allele represents approximately 50% of the signal, as expected. The percentage of wild-type allele calculated from the data is corrected to include hepatocyte DNA only (see Materials and Methods).