Fig. 7. Duct cell progenitors do not express Ngn3. Ngn3-Cre transgenic animals are crossed with the Z/AP reporter line and HPAP expression in pancreas is characterized in postnatal mice (A,B) or embryos (C,D). (A,B) In 1- or 8-week-old animals, only islet cells express HPAP (i, islet, broken red line), and no duct cells express HPAP (d, duct, broken green line). (C) In E14.5 pancreas, HPAP+ cells reside in duct-like structures (dl, duct-like structures, broken green line), as identified by the presence of a hole. Yet, these HPAP+ cells are endocrine progenitors (ep, red arrow). (D) At E16.5, the HPAP+ cells or endocrine progenitors (ep, broken red lines) form cord-like or islet-like structure and some duct-like structures that do not express HPAP (dl, broken green lines) are also observed. Scale bar: 25 µm.