Requirements for Wnt signaling in pharyngeal arch cell proliferation.

<p>(A–L) Whole mount ISH for <i>pcna</i> in embryos fixed at 3–22 hours post-heat shock (hphs), lateral views, anterior to the left (all heat shocked at 22 hpf). (A–D) <i>pcna</i> is expressed throughout arches, brain and eyes. (E–H) dkk1+ embryos have reduced <i>pcna</i> expression at 3 hphs (E), severe reductions at 6 hphs (F) and virtually no arch expression at 8 hphs (G), before expression returns at 22 hphs (H). (I–L) dntcf3+ embryos show reduced <i>pcna</i> expression at 3 hphs (I), and virtually no expression at 6 hphs (J, K) before expression rebounds between 8–22 hphs (L). (M) Histogram quantifying percentages of dkk1+ and dntcf3+ embryos with moderate versus severe reductions in <i>pcna</i> expression. Scale bar: 100 µm.