Fig. 8 foxA2 mimics gain-of-function phenotypes of Cyc/Nodal signals and rescues floor plate in cyc (Nodal) signalling-deficient embryos. Misexpression of foxA2-ER causes ectopic expression of netrin1 (A), gfp (B), and shh (C) in the neural tube of zebrafish embryos (white arrowheads, e). (D, F) netrin1 and shh expression pattern in oep mutants. Note that the expression in the ventral neural tube is absent (blue arrowhead) while the hypochord (black arrowhead, h) and notochord (red arrowhead, n) express normally netrin1 and shh, respectively. (E, G) Injection of foxA2-ER mRNA into oep embryos rescues netrin1 (E) and shh (G) in the neural tube at 24 hpf. Orientation of embryos: anterior is left and dorsal up. Abbreviations: e, ectopic floor plate (white arrowhead); f, floor plate (black arrow). Scale bar represents 50 μm (A–C) and 25 μm (D–G).
Reprinted from Developmental Biology, 252(1), Rastegar, S., Albert, S., Le Roux, I., Fischer, N., Blader, P., Müller, F., and Strähle, U., A floor plate enhancer of the zebrafish netrin1 gene requires Cyclops (Nodal) signalling and the winged helix transcription factor FoxA2, 1-14, Copyright (2002) with permission from Elsevier. Full text @ Dev. Biol.