Figure 1

Expression of Arx and Brn4 in E16.5 pancreata of wild type, Nkx2.2^-/- and Pax6^-/- mice. (A, B) Arx is expressed in wild type glucagon⁺ cells. (A, inset) Moreover, Arx⁺/glucagon^- cells are detectable at this stage. (B, C, inset) Arx or Brn4 can be detected in a subset of ghrelin⁺ cells. (D, inset) In Nkx2.2-mutant pancreata some of the remaining glucagon⁺ cells do not express Arx. (E, inset, F) Most Nkx2.2-deficient ghrelin⁺ cells express Arx but only rarely Brn4. (G, H) Arx is expressed in pancreata of Pax6^-/- mice and co-localizes with most ghrelin⁺ cells. Scattered Arx⁺/ghrelin^- and ghrelin⁺/Arx^- cells can be detected. (I, inset) Brn4 is expressed in a subset of ghrelin⁺ cells and labels a ghrelin^- cell population in Pax6-deficient mice. Counterstaining with DAPI. (J-L) The percentages of Arx⁺/glucagon⁺, Arx⁺/ghrelin⁺ and Brn4⁺/ghrelin⁺ cells in pancreata of wild type (WT), Nkx2.2^-/- (N2.2) and Pax6^-/- (P6) mice within the total glucagon⁺ and ghrelin⁺ cell populations, respectively, are depicted. (M) Quantitative RT-PCR of Arx, Pax6 and Nkx2.2 mRNA in wild type, Nkx2.2^-/-, Pax6^-/- and Arx^- E16.5 pancreas. (N) Quantification of Arx⁺ cells at E16.5 in pancreata of wild type, Nkx2.2^-/- and Pax6^-/- mice (n = 3 pancreas per genotype). Single-factor ANOVA coupled to Newman-Keuls test was applied and p-values < 0,05 were assessed as statistically significant compared to wild type. Statistical significance is achieved with the assumption of a normal distribution. Error bars represent SEM. (original magnification: 400×, Insets magnification: 4×).