Figure 6

MafB and Krox20 are dependent on ERK1/2 but not on Akt activation. HH7⁺-8 embryos (a-d, f-i,k-m) or HH9 (e, j) were explanted and beads soaked in specific inhibitors were placed in the caudal hindbrain. Afterwards, embryos were analyzed for Krox20, MafB or Fgf3 expression. Pharmacological treatments were as follows: DMSO (a, f,k), FGFR inhibitor SU5402 (b, e,g,j,l), ERK1/2 inhibitor PD184352 (c, h,m), or PI3K inhibitor LY294002 (d, i), during 6 h. Embryos are shown in whole-mount with anterior to the top.