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Fig. 5. Midbrain cells that cannot respond to Fgf signalling acquire forebrain
character. Embryos were injected with 400 pg XFD-mRNA (A), grafts of
these donor embryos were transplanted to a wild-type host embryos (B) and
fixed at indicated stages prior to staining procedures (C). Arrows indicate
transplanted cells. (D,F) Cell clones in the midbrain express the forebrain
markers pax6.1 and efna4. Transplanted cells contain
rhodamine dextran (E,G), but do not express the midbrain marker Engrailed, as
visualized by
-Engrailed antibody 4D9 staining (H-J). Control
transplantations without XFD mRNA show co-localization of rhodamine
dextran and
-Engrailed staining (K-M). (J,M) Superimposed pictures of
H,K and I,L. Transplanted cells do not express any of the hindbrain markers
gbx1, fgf8 or krox20 (N,O). a, anterior; fb, forebrain; hb,
hindbrain; p, posterior; r3, rhombomere 3.