Figure 4.

Phox2b⁺ and PGP9.5⁺ cells in E11.5 GI mesenchyme. Figure shows Phox2b (panels A and B) and PGP9.5 (panels C and D) staining of adjacent histological sections obtained from littermate Hlx^+/+ (panels A and C) and Hlx^-/- (panels B and D) embryos at E11.5. Staining was performed as described in Methods with the primary antibody at these titers: Phox2b, 1:500; PGP9.5, 1:1,200. Examples of Phox2b⁺ and PGP9.5⁺ cells are indicated by blue arrowheads. Black bars, 100 μm.