DEV02288 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure 1 -

  Fig. S1. Midline expression of Hedgehog in hedgehog mutant embryos partially rescues Engrailed expression. (A) In hedgehog mutants at stage 13, only one to three Engrailed-positive (black) midline cells remain. (B) Expression of midline Hedgehog (brown) increases the number of Engrailed-expressing (black) midline cells in hedgehog mutants, but not all midline cells express Hedgehog. (C) In wild-type embryos at stage 10, all midline cells express Single-minded (black) and a subset of midline cells expresses Engrailed (brown). (D) In hedgehog mutants, the expression of Single-minded disappears from stage 10 and ectodermal Engrailed expression is lost. C and D show the neuroblast layer. Ventral views, anterior to the left.

• Supplemental Figure 2 -

  Fig. S2. Engrailed expression at the midline depends on the expression of Hedgehog in the neuroectoderm and the midline. (A) Until stage 10, Hedgehog (Hh, black) is detectable in the midline and the adjacent neuroectoderm. (B) At stage 11, Hedgehog disappears from the midline but continues to be expressed in the adjacent neuroectoderm and developing CNS. Ventral views, anterior to the left; brackets outline the midline. (C) Engrailed expression in the midline is sensitive to the loss of Hedgehog from stage 10 to stage 12. hh^ts2 embryos were shifted to the restrictive temperature at various stages of development. Red bars show time at the restrictive temperature (29°C), indicating periods of Hedgehog inactivation. The green bar marks the temperature-sensitive period; black bar depicts hedgehog protein expression at the ventral midline. Engrailed (En) expression in midline cells is not affected (+), reduced in most segments (+/-) or reduced in all segments (-). Embryos were examined at stages 13 to 17.