Fig. 3. Prospective neural fate in the vegetal ectoderm is initiated independent of the organiser and antagonism of Bmp activity. Lateral views of gastrula stage wild-type (A,F,K), chordin mutant (din^-/-) (B,G,L), bmp2b-injected (C,H,M) and ichabod mutant (ich^-/-) (D,E,I,J,N,O) embryos with dorsal towards the right (when discernable). Genes analysed by in situ hybridisation are indicated to the left of each row. In E, J and O, embryos were double stained with a probe for ntl, which marks marginal mesoderm cells. The gap (black arrowhead) between ntl and p63 expression domains complementarily expresses sox3 and zic2.2 in ich^-/- embryos. The white arrowheads in A-D indicate the position at which sox3 is expressed in prospective forebrain neural tissue in wild-type embryos. Brackets in F-H,K-M indicate the reduction in prospective anterior neural plate size in din^-/-, bmp2b-injected and ich^-/- embryos.