Kinkel et al., 2009 - Cyp26 enzymes function in endoderm to regulate pancreatic field size. Proceedings of the National Academy of Sciences of the United States of America   106(19):7864-7869 Full text @ Proc. Natl. Acad. Sci. USA

Fig. 1 Expression of cyp26 genes in late zebrafish gastrulae. (A–G) Expression of cyp26a1 from 8 to 13 hpf. Shown are whole mounts, animal pole up, dorsal views (A–C) and lateral views (D–G). Arrowheads indicate endodermal expression. (H and I) Double in situ hybridizations with cyp26a1 (purple) and myod (red) to show paraxial mesoderm. Embryos are deyolked and flat-mounted, and anterior is to top of page. Arrowheads indicate anterior limit of myod expression. (J) cyp26a1 expression in DMSO carrier-treated embryo at 12 hpf, whole-mount, lateral view. (K) cyp26a1 expression in embryo treated with 0.1 μM RA from 5.25 hpf; note up-regulation of expression. (L) cyp26a1 expression in 10 μM 4-(diethylamino)benzaldehyde (DEAB)-treated (RA-deficient) embryo from 5.25 hpf; note absence of anterior trunk expression. (M) Transverse optical section through anterior trunk at 12 hpf. (N) Transverse section through anterior trunk of RA-treated embryo as in K; note up-regulation of endodermal cyp26a1. (O) cyp26b1 expression at 12 hpf, whole-mount, lateral view. (P) cyp26b1 expression in embryo treated with 0.1 μM RA from 5.25 hpf. (Q) cyp26c1 expression at 12 hpf, whole-mount, lateral view. (R) Transverse section through anterior trunk, embryo treated with 0.1 μM RA from 5.25 hpf; note up-regulation of endodermal cyp26b1. Arrowhead indicates anterior trunk, and for M, N, and R arrowheads indicates anterior trunk endoderm.

Fig. 2

Cyp26 inhibition expands the pancreas anteriorly. (A and B) pdx1 labels cells of the pancreas and anterior small intestine. (C and D) insulin (ins) labels β-cells. (E and F) insulin (ins), lateral view. (G and H) glucagon (gcga) labels α-cells. (I and J) somatostatin 2 (sst2) labels δ-cells. (K and L) islet1 labels endocrine pancreas; lateral view. (M and N) cebpa labels liver and intestine. (O and P) foxa2 labels pharyngeal endoderm. Arrowheads indicate endoderm. The dorsal view is shown unless otherwise indicated, anterior to left.

Fig. 3

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.

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EXPRESSION / LABELING:
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Stage: Prim-5
Acknowledgments:
ZFIN wishes to thank the journal Proceedings of the National Academy of Sciences of the United States of America for permission to reproduce figures from this article. Please note that this material may be protected by copyright. Full text @ Proc. Natl. Acad. Sci. USA