Formin inhibition at gastrula and neurula stages results in abnormal molecular patterning of GRP.

(A-B’) Representative images of molecular patterning in the GRP. Dorsal explants of stage 18 neurula embryos after control treatment (A,B) and SMIFH2 administration (A’,B’) at stages 10–18. In situ hybridisation was performed with probes specific for sox17 (A,A’) and tekt2 (B,B’). (C and C’) Representative images of nodal1 expression pattern in the GRP. Dorsal explants of stage 18 neurula embryos after control or SMIFH2 treatment at stages 10–18. (D and D’) Histological sections through GRP demonstrate the position of nodal1-positive cells in the prospective somitic mesoderm. Arrows indicate areas of superficial nodal1-positive cells.