Fig. 6. NGN3+ cells contribute to the renewal or maintenance of islets in adult mice. Tamoxifen was injected into 3- or 8-week-old Z/AP;Ngn3-Cre-ER^TM animals and HPAP expression was examined 1, 3, or 7 days later. (A) A control showing that no HPAP+ cells are detected in an 8-week-old Ngn3-Cre-ER^TM; Z/AP pancreas without TM injection. (B) HPAP+ cells detected in islets 1 day after TM was injected into an 8-week-old mouse. (C) An enlarged area of B. (D) HPAP+ cells in islets 7 days after TM injection. In no case were HPAP+ cells observed in non-islet structures (d, duct, broken green lines; i, islets, broken red lines). Scale bars: in B, 25 µm for A,B; in D, 25 µm for C,D.