Fig. 2

The early ptf1a lineage generates a small fraction of PNC and endocrine cells. A: Experimental setup. B–G: In all the panels, ptf1a lineage is indicated by nuclear-mCherry expression (red). B, C: Immunofluorescence for Nkx6.1 (green) labels PNCs. B: In some pancreata, the ptf1a lineage and PNCs show no overlap. C: In some pancreata, ptf1a lineage–labeled cells are traced into PNCs. Arrows point to colabeling events. D: In some pancreata, the ptf1a lineage has no demonstrable contribution to endocrine cell types. ptf1a:GFP transgene (green) shows current expression of ptf1a, which, at 6 dpf, is limited to acinar cells. Endocrine cells are labeled by a mixture of antibodies against Insulin (Ins) and Glucagon (Gluc), white. E: In a few pancreata, some of the cells derived from the ptf1a lineage are co-labelled by the ins:nuc-GFP transgene (green), which is visualized in the nuclei of Insulin-secreting cells. Arrows point to co-labeling events. F: 4-OHT treatment at 6h-32hpf. In the pancreas shown, no ptf1a lineage-labeled cells can be observed in the endocrine compartment (outlined) or PNCs (Nkx6.1, green). G: 4-OHT treatment at 6h-6dpf. Nkx6.1, blue. Arrows point to ptf1a lineage-labeled endocrine cells. Arrowhead points to ptf1a lineage-labeled PNCs. Scale bar = 50 µm.