Fig. 3.
Ptf1a-expressing cells are acinar-restricted after birth. (A) Postnatal/adult lineage-tracing schematic. (B,C) Ptf1aCreERTM;R26REYFP embryos Tam-pulsed at E18.5, analyzed 3 weeks after birth showing EYFP exclusively in acini. (D) P21; percentage of each pancreatic cell type expressing EYFP. (E,F,H,I) 1-month-old Ptf1aCreERTM;R26REYFP mice treated with Tam were chased for (E,F) 1 week or (H,I) 6 months; EYFP was only in CpaI+ acinar cells. (G,J) Comparing EYFP+ traced cells at P36 (G) or 7 months (J) showed similar acinar labeling, suggesting homeostatic acinar self-replication. (K-L) EYFP was absent from (K,K′) Ck19+ or (L) Hnf1β+ CAC cells after 6-month chase; diagrammed as Ptf1a-expressing cells not producing CACs. (M-M‴) Ptf1a protein was undetectable in Sox9+Ck19+ CACs. Scale bars: 50 μm.