Fig. 2. Analysis of neural plate patterning in Fgf8^Null/Neo embryos. Whole-mount in situ hybridization showing Otx2 expression (A-B'), Six3 expression (C-D') and Foxg1 expression (E-F') in 9- to 10-somite embryos. The developmental stage of embryos is indicated in the lower left corner by the number of somites (s). On lateral views of embryos, anterior is located to the right; on frontal views, anterior is located towards the top. In the neural plate of the mutants, Otx2 expression is slightly expanded rostrally (arrowheads in B,B') and caudally at the level of the midbrain/hindbrain boundary (arrowheads in A,A'); Six3 expression is intensified in caudal regions (arrowheads in C-D'); and Foxg1 expression is slightly reduced (arrowheads in F,F'). Foxg1 expression is not detected in the mutant pharyngeal region (arrows in E,E').