Figure 5.

Before morphologic differences, Kras mutation alters the abundance of acinar- and duct-derived cells 2 weeks after duct obstruction. (A and B) Gomori’s trichrome staining showing fibrillar collagen in blue in Ptf1a^CreERTMKras^G12D (A) and in CK19^CreERT2Kras^G12D (B) mice. (C) Percent collagen+ area per genotype showing no statistically significant differences. (D–F) Pancreata from 3 different Ptf1a^CreERTMKras^G12D mice showing loss of nearly all amylase staining distal to ligation 2 weeks after PDL. Note positive staining in region proximal to ligation in (D). (G and H) Ptf1a^CreERTMLSL-Kras^G12DR26R^EYFP pancreas (G) and CK19^CreERT2LSL-Kras^G12DR26R^EYFP pancreas (H) were labeled for the EYFP protein (brown) distal to ligation (tail). (G’ and H’) are corresponding proximal regions (heads) of the pancreata shown in (G) and (H). (I) Quantification of enrichment for EYFP+ (CreERT-activated) cells. Enrichment score is the ratio of the percent of non-endocrine epithelium that is EYFP+ in the tail region to the percent that is EYFP+ in the unaffected head region. (J) Similar to (I), but only ductal epithelium, not acinar epithelium, was quantified. Size bars, 100 μm. *P < .05; **P < .01.