Fig. 3

Expression of Pax7 at 24 hr following heat-shock induction of Bmp2b. A: Expression of Pax7 (green) in embryos that were injected with the hs-bmp construct, but not heat shocked. Pax7 cells are distributed along the borders of the myotome and in the horizontal myosepta. Myosin is shown in red. B: Pax7 expression (green) in an embryo that was heat shocked at 8S to induce overexpression of BMP. The number of Pax7-expressing cells is increased in somites along the anterior-posterior axis. C: Pax7 expression in an embryo that was heat shocked at the 17S stage to induce overexpression of BMP. A strong increase in the number of Pax7-expressing cells is evident in the posterior somites, particularly around somite 17. There is also a smaller increase in the number of Pax7-expressing cells in the anterior portion of the somite. Numbers above somites indicate the number of Pax7+ nuclei in that somite. Scale bar = 50 μm.