Figure 1—figure supplement 2.

To verify that MZsmad2 and MZoep embryos express Nodals in the YSL, we stained for cyclops and squint mRNA by smFISH. All depicted embryos were counterstained with DAPI to mark nuclei and α-eCdh1 to mark cell boundaries (A) Wild-type embryos express squint mRNA in the YSL and blastoderm at 50% epiboly. (A’) Enlarged view of area within the white box from panel (A). (B) MZsmad2 embryos express squint mRNA in the YSL, but not the blastoderm, at 50% epiboly. (B’) Enlarged view of area within the white box from panel (B). (C) MZoep embryos express squint mRNA in the YSL, but not the blastoderm, at 50% epiboly. (C’) Enlarged view of area within the white box from panel (C). (D) Wild-type embryos express cyclops mRNA in the YSL and blastoderm at 50% epiboly. (D’) Enlarged view of area within the white box from panel (D). (E) MZsmad2 embryos express cyclops mRNA in the YSL, but not the blastoderm, at 50% epiboly. (E’) Enlarged view of area within the white box from panel (E). (F) MZoep embryos express cyclops mRNA in the YSL, but not the blastoderm, at 50% epiboly. (F’) Enlarged view of area within the white box from panel (F).