Fig. 4

Fig. 4 Zic2b promotes timely neural crest induction. (A–L) Wild-type embryos stained by two-color ISH for expression of dlx3b, foxd3, zic2a and zic2b. (A,B) At 70% epiboly, weak expression of dlx3b (orange) and zic2a (purple) form two adjacent domains. (C,D) These domains are stronger by 90% epiboly but continue to overlap, suggesting the neural plate border is not completely formed. (E,F) At 1S, dlx3b (orange) and zic2a (purple) begin to separate. (G,H) Foxd3 (orange) straddles the border beginning at 1S, overlapping neural and non-neural (dlx3b, purple) markers. (I) At 1S, NC marker foxd3 (orange) and zic2b (purple) overlap at the neural plate border. (J,K) From 3-6S, zic2b (orange) is expressed in two anterior, bilateral domains from which zic2a (purple) is excluded. (L) Zic2b expression at the neural plate border extends into the posterior neural keel. (M,N) Sna1b expression is unchanged in zic2a morphants during early somitogenesis (37/48, 5 exp.). (O) Zic2b morphants have reduced (19/47, 5 exp.) or absent (16/47, 5 exp.) NC domains. (P) The sna1b domain is reduced (11/38, 5 exp.) or more frequently absent (24/38, 5 exp.) in double zic2 morphants. (A,C,E and G) are lateral views, anterior to the right. (B, D, F and H) are high magnification images of (A, C, E and G), respectively. (I–P) are dorsal views with anterior to the left.