Fig. 5

PNC differentiation is regulated by endogenous RA signaling. (A and B) in situ hybridization for neuroD expression to detect 2° islets in 5 dpf pancreata from larvae transgenic for both the Notch-responsive creER^T2driver, Tg(Tp1glob:creER^T2)^jh12, and the dnRAR cre responder, Tg(ubb:loxP-eCFP-loxP-dnRAR-GFP)^jh39. These larvae had been incubated at 2 dpf with either vehicle (A) or 4OHT (B). (C) Average number of 2° islets/pancreas in vehicle or 4OHT treated larvae calculated by counting neuroD expressing islets. (D–G) Fluorescence immunostaining to detect hormone-expressing cells (insulin⁺/glucagons⁺/somatostatin⁺), facilitating quantification of 2° islet cells in larvae that were treated from 2–5 dpf with either vehicle (D), or 4OHT (E), or vehicle+DEAB (F). (E′′) enlarged image of (E′). (G) Average number of 2° islet cells/pancreas in vehicle, 4OHT, and vehicle+DEAB treated larvae calculated by counting for the number of hormone-expressing cells. **p<0.001. White dashes outline pancreata. 2° Islets in the tail region of the pancreas are indicated by arrowheads. N=number of larval pancreata quantified. Error Bar=SE. Scale Bar, 100 μm.