Figure 4
From: Boundary cells regulate a switch in the expression of FGF3 in hindbrain rhombomeres
Ablation of a boundary results in sustained rhombomeric expression of FGF3. (A-C): Diagram and photographs of a unilateral ablation of the r3/r4 boundary in 12 ss embryos (A, B), and after insertion of a silicon piece into the gap (C). (D-F): Flat-mounted hindbrains of embryos in situ hybridized with FGF3 probe at 28 ss. FGF3 continues to be expressed in r4 in the manipulated side (D, E, asterisks), while downregulated from r4 of the control side. In an embryo in which the ablated r3/r4 boundary was allowed to regenerate, FGF3 was downregulated from r4 and upregulated in the re-formed boundary (F, asterisk). In all images, anterior is at the top, arrows mark the position of the grafted piece and r4 is marked.