(A) In situ hybridization examining Vent2, Oct25, Id3, and TF-AP2 in blastula stage (stage 9) embryos injected unilaterally with Sox2, Sox3, Sox9 or Sox10. (B) Schematic of Sox9 and Sox9 protein domains. (C) In situ hybridization examining Vent2 and Id3 expression in blastula stage (stage 9) embryos injected unilaterally with wildtype or mutant forms of Sox9. (D) In situ hybridization examining Vent2 and Id3 expression in blastula stage (stage 9) embryos injected unilaterally with wildtype or mutant forms of Sox10. Asterisk (*) denotes injected side of the embryo as marked by staining of the lineage tracer β-galactosidase (red).