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. Author manuscript; available in PMC: 2013 Jul 23.
Published in final edited form as: Nature. 2012 Mar 14;483(7389):289–294. doi: 10.1038/nature10838

Figure 1. An ANR-like signalling centre in S. kowalevskii.

Figure 1

a-h, S. kowalevskii and mouse in situ hybridizations for markers of ANR and telencephalon. S. kowalevskii embryos are at double groove stage (36 hrs), and are shown in dorsal view with anterior to top left, except where noted. Embryos are optically cleared except in o, q insets and r-w. Mouse embryos are at stage ~E8.5. a, S. kowalevskii sfrp1/5 expression. b, frontal view of mouse sfrp1 expression, arrow denotes ANR. Inset shows lateral view. c, S. kowalevskii fgf8/17/18 expression. d, mouse fgf8 expression, arrow denotes ANR. e, S. kowalevskii hh expression. f, S. kowalevskii fgf-Sk1 expression. g, frontal view of double fluorescence in situ hybridization for hh and fgf-Sk1. h, fz5/8 expression. i, AP expression topologies in S. kowalevskii and mouse embryos. Anterior to top. j-k, foxg (j) and rx (k) expression in embryos treated with SU5402. l, m, foxg (l) and rx (m) expression in embryos treated with DMSO. n, expanded apical fgf-Sk1 expression in an embryo injected with fz5/8 siRNA. o, retracted rx expression in an embryo injected with fz5/8 siRNA. p, fgf-Sk1 expression in a siRNA control embryo. q, rx expression in a siRNA control embryo. Insets in o, q show frontal views of uncleared embryos. r, wild type fgf-Sk1 expression. s, fgf-Sk1 expression in descendants of a blastomere injected with β -catenin siRNA. t, merged darkfield/fluorescence images showing clonal descendants of injected cell (green). u, wild-type rx expression. v, rx is not expressed in descendants of a blastomere injected with β -catenin siRNA. w, merged darkfield/fluorescence images showing location of the β-catenin deficient clone (green). x, fgf-Sk1 expression in an embryo injected with hh siRNA. y, fgf-Sk1 expression in a siRNA control embryo. Scale bars = 100 μm in S. kowalevskii, and for mice, 200 μm in (b) and 500 μm in (d). Abbreviations: col, collar; di, diencephalon; hb, hindbrain; mb, midbrain; pr, proboscis; tel, telencephalon; tr, trunk. *, note shh is expressed in the medial ganglionic eminence, near to the ANR.