Fig. 3. Foxn4 is expressed in common precursors of V2a and V2b interneurons. (A,B) Foxn4^+/- mouse embryos were labelled by double immunohistochemistry for ß-galactosidase (ß-gal, green) and either Chx10 or Gata3 (red). Confocal microscopy reveals cells that are double labelled for ß-gal and either Chx10 (A) or Gata3 (B), suggesting that Foxn4-expressing progenitors give rise to both V2a and V2b interneurons (INs). (C-F) Consistent with this conclusion, Foxn4-positive progenitors co-express Mash1 (C) and Lhx3 (D), markers that later segregate into V2b and V2a INs respectively. Individual Foxn4/Lhx3 double-positive cells (boxes E and F) are reproduced, with fluorescence channels separated, in the lower left and lower right corners, respectively, of D.