Epithelial Tissues Have Varying Degrees of Susceptibility to KrasG12D-Initiated Tumorigenesis in a Mouse Model
Figure 8
Cre-mediated recombination of the LSL-KrasG12D allele in different tissues.
A. DNA was extracted from the indicated tissues of three different mice and subjected to 35 cycles of PCR that would detect both the wildtype Kras allele (271 bp) and the recombined LSL-KrasG12D allele (310 bp) but not the unrecombined LSL-KrasG12D allele. Tissues examined: 1) tail, 2) small intestine, 3) liver, 4) pancreas, 5) kidney, 6) stomach, and 7) colon. Strong recombined bands were detected for small intestine, pancreas and colon and weaker bands for stomach, kidney and liver, while recombination was never detected in tail DNA. B. The amount of recombination of an unaffected tissue, the small intestine, was compared to the amount in an oral papilloma in which all or nearly all of the epithelium should have a recombined Kras allele. For three different mice, DNA was prepared from total oral tissue (lanes 1–3), isolated papilloma tissue (lanes 4–6) and total small intestine tissue (lanes 7–9) and subjected to 30 cycles of PCR. Little recombination can be detected in total oral tissue while the recombination is abundant in the isolated papilloma (upper band in each lane). The amount of recombination in the small intestine was intermediate between these two populations.