Cyp26 enzymes set the anterior limit of the insulin domain. (A) Wild-type insulin domain. (B) insulin is expanded in Cyp26a1-deficient gir mutants. (C–E) Knockdown of Cyp26b1 and Cyp26c1 singly or in combination does not expand insulin. (F and G) Knockdown of Cyp26b1 or Cyp26c1 in gir mutants expands the pancreas as with gir alone. (H) Deficiency in all 3 Cyp26 enzymes expands the pancreas more than with Cyp26a1 deficiency alone. All panels show 24 hpf, dorsal view, anterior to the left, 200x magnification. (I) Size of the insulin domain in response to Cyp26 deficiency. Note that the Cyp26a1 morpholino does not expand the pancreas as dramatically as in gir mutants. Wild-type, n = 19; a1MO, n = 10; b1MO, n = 34; c1MO, n = 28; b1 + c1 MO, n = 20; R115866, n = 10; gir + b1MO, n = 17; gir + c1MO, n = 11; gir + b1 + c1MO, n = 11.