Fig. 5

wdr68 acts upstream of the edn1 pathway. A) In situ hybridization (ISH) with dlx2 on 12 somites stage embryos. Wild type and dys/dys mutant animals were indistinguishable. B) ISH on 20 somites stage wild type sibling animal with edn1 probe. C) dys/dys homozygotes display reduced edn1 expression at 20 somites stage. D) ISH on 28 hpf wild type sibling animal with edn1 probe. E) dys/dys homozygotes display reduced edn1 expression at 28 hpf. F) ISH on 41 hpf wild type sibling with bapx1 probe. G) dys/dys homozygotes display reduced bapx1 expression. H, I, J, K, L, M, N, O) Red arrowhead indicates 1^st arch expression domain, blue arrowhead indicates 2^nd arch expression domain. H) ISH on 28 hpf wild type sibling with hand2 probe. I) dys/dys homozygotes display reduced 1^st arch hand2 expression, red arrowhead. Red dotted outline indicates expression in developing heart. J) dys+wdr68MO animals display reduced hand2 expression in both 1^st and 2^nd arches, red and blue arrowheads, respectively. K) edn1-MO animals lack hand2 expression in both the 1^st and 2^nd arches. L, M, N, O) Red asterisk indicates olfactory expression domain. Black asterisk indicates ear expression domain. L) ISH on 28 hpf wild type sibling with dlx3b probe. M) dys/dys homozygotes display reduced 1^st arch dlx3b expression, red arrowhead. N) dys+wdr68MO animals display reduced dlx3b expression in both 1^st and 2^nd arches, red and blue arrowheads, respectively. O) edn1-MO animals lack dlx3b expression in both the 1^st and 2^nd arches. P, Q, R, S) Red underline indicates 1^st arch region for sox9a expression. Black underline indicates 2^nd arch region for sox9a expression. P) ISH with sox9a probe on 28 hpf wild type sibling. Q) Reduction of 1^st arch sox9a expression without significant effect on 2^nd arch sox9a expression in dys/dys animals. R) Injecting dys animals with wdr68MO caused further reduction of 1^st arch sox9a expression without substantial effects on 2^nd arch sox9a expression. S) edn1-MO animals show reduced but still detectable sox9a expression in both the 1^st and 2^nd arches.