Fig. 6. Loss of Foxg1 from retina or chiasm impairs outgrowth of dorsonasal retinal axons on chiasm cells in culture. (A-D) Co-cultures of Foxg1^+/± or Foxg1^-/- dorsonasal (DN) retinal explants with dissociated Foxg1^+/± or Foxg1^-/- chiasm cells; immunohistochemistry is for the axonal marker neurofilament (NF; green) and the RGC marker Brn3a (red); the nuclear counterstain TO-PRO-3 (blue) reveals cells in the retinal explant and surrounding dissociated chiasm cells. Cultures in A and C are shown at half the magnification of those in B and D. (A'-D') Brn3a expression in co-cultures A-D, respectively. (E) Mean percentage axon coverage (±s.e.m.) 45 µm from the retinal explant, showing significant differences among the four combinations. (F) Mean lengths of the five longest neurites (± s.e.m.). (E,F) Numbers of explants are in parentheses. One-way ANOVA revealed significant differences in outgrowth among retinal explants. Significant differences with P values are indicated above each bracket. Scale bars: 200 µm in A,C; 100 µm in B,D; 10 µm in A'-D'.