Fig. 5. Foxa1/2 are required for early and late differentiation of mDA neurons at E12.5. (A-L) Coronal sections of mouse embryos. (A-H) The number of immature Nurr1⁺ TH^- (A-D) and En1⁺ TH^- (E-H) neurons (green) increases at the expense of mature Nurr1⁺ TH⁺ (A-D) and En1⁺ TH⁺ mDA (E-H) neurons (yellow) in Foxa1/2 single-mutant embryos compared with the corresponding numbers in control embryos. The total number of neurons (immature plus mature mDA neurons) is reduced only in Foxa2cko;Foxa1^-/- embryos when compared with the total number in control embryos. (I-L) TH⁺ AADC⁺ mature neuron number decreases in all mutant compared with control embryos (see quantification in Fig. 6). Scale bars: 75 µm.