Fig. 1.

Efficient deletion of ISL1 in the Isl1CKO pancreas during the primary transition. a Representative whole-mount immunolabeling of the dorsal pancreas shows that NEUROD1 matches Neurod1^Cre expression visualized by anti-CRE antibody in the PDX1⁺ pancreatic domain (arrowheads indicate cells co-expressing CRE and NEUROD1). b, c A reduced number of ISL1⁺ cells shown in the Isl1CKO dorsal pancreatic epithelium delineated by the expression of PDX1 (whole mounts). d–f Higher-magnification images show significantly reduced number of cells expressing ISL1 in NEUROD1⁺ area in the Isl1CKO dorsal pancreas compared to littermate controls. Data are presented as mean ± SD (n = 5 pancreases per genotype), unpaired t-test (****P < 0.0001). Scale bars: 50 μm