Fig. 7. Expression of Nkx6.1 or Nkx6.2 in the Pdx1 domain restores Myt1 expression in Nkx6.1 mutant embryos. (A-D) Immunofluorescence detection of Myt1 (red) and insulin (Ins, blue) in pancreata from wild-type (A), Nkx6.1^-/- (B), Nkx6.1^-/-;Pdx1-Nkx6.1 (C) and Nkx6.1^-/-;Pdx1-Nkx6.2 (D) embryos at E14.5. (B-D) Nkx6.1^-/- embryos have reduced Myt1 expression (B), which is restored by expression of the Pdx1-Nkx6.1 (C) or Pdx1-Nkx6.2 (D) transgenes. (E) Morphometric quantification of the number of Myt1⁺ cells over total pancreatic area in E14.5 embryos reveals an average reduction of Myt1⁺ cells in Nkx6.1^-/- to 14% of wild-type numbers (n=3). The Pdx1-Nkx6.1 or Pdx1-Nkx6.2 transgene restores the number of Myt1⁺ cells in Nkx6.1^-/- mutants to 75% and 70% of wild-type values, respectively (n=3). Values in E represent averages ±s.e.m. Scale bar: 50 µm.