DEV02426 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure 1 -

  Fig. S1. Effect of Shh derived from notochord and floor plate and Wnt1 produced from the dorsal neural tube on lateral rectus EOM development. (A-D) Lateral views of embryos at HH19, displayed as in Fig. 9, stained for paraxis mRNA (blue) and for intermediate neurofilaments using the RMO270 antibody (brown). Shh (bead marked by asterisk) prevented the expression of paraxis (B, open arrowhead), suggesting that it does not participate in the positive control of lateral rectus EOM development. RatB1 cells expressing Wnt1 (stained with Celltracker Orange, asterisk) slightly reduced the expression of paraxis (D, open arrowhead). Thus, Wnt1 also does not support lateral rectus specification. Scale bar: 200 μm.

• Supplemental Figure 2 -

  Fig. S2. Limited ability of the isthmus to signal to mesodermal tissues. (A,B) Lateral views of embryos at HH22, stained for Fgf8 expression; anterior towards the top, dorsal towards the left. (C,D) Vibratome cross sections of operated area, dorsal towards the top. (A,C) Fgf8 loaded beads implanted into the flank of HH16 embryos readily triggered the development of an ectopic limb as evidenced by the emergence of an outgrowth carrying an Fgf8-expressing apical ectodermal ridge. (B,D) When the neural tube from posterior mid- to anterior hindbrain levels was grafted into the flank, then strong isthmic (i) expression of Fgf8 was maintained. The graft grew considerably and expanded into the peritoneal cavity. The somatopleural lateral mesoderm increased in thickness, suggesting that the graft had some mitotic effect on the host tissues. However, an aer-carrying ectopic limb did not develop. Abbreviations: aer, apical ectodermal ridge; da, dorsal aorta; el, ectopic limb; dmg, dorsal mesogaster; fl, forelimb; hl, hindlimb; i, isthmus; mn, mesonephros; not, notochord; ptc, peritoneal cavity (coelom); smpl, somatopleura; splpl, splanchnopleura. Scale bar: 250 μm in A,B; 200 μm in C,D.