Fig. 5. Expression of various neural plate markers following Delta2/Notch inhibition or ectopic expression. The marker analysed is indicated on the left and embryo treatment is indicated above the panels. Graphs show the percentage of embryos with ectopic, strong or weak expression according to the key indicated below. The same key is used for all subsequent figures. For Ci-Hesb and Ci-Chordin, `weak' means reduced expression compared with the majority of controls. For the remaining markers, `strong' means at least one A-line neural precursor cell with strong expression and `weak' means at least one cell with downregulated expression. Occasionally, following disruption of Delta2/Notch signalling, ectopic expression was seen for Ci-FGF8/17/18 and Ci-ephrinAb. This ectopic expression appeared in column 4. Following FOG::Delta2 electroporation (abbreviated to FOG::D2), Ci-FGF8/17/18 exhibited frequent unilateral expression. Of those scored positive, 49% expressed Ci-FGF8/17/18 on one side only (compared with 9% of control embryos from the same batches). Ectopic expression of Ci-COE following FOG::Delta2 electroporation appeared in column 3 (A9.30) in the majority of cases (see text for details) with 54% of these cases exhibiting unilateral A9.30 expression and 46% bilateral. Ectopic expression of Ci-MRF was observed only in column 3 (A9.29). Of those exhibiting ectopic expression, 66% had column 3 (A9.29) expression on one side only. In most cases, column 3 (A9.29) expression of Ci-MRF appeared slightly weaker than the expression in column 4 (A9.31). For Ci-FoxB, expression in both control and treated embryos was frequently (around half of those scored positive) observed on one side only. Arrowheads point to ectopic expression on the panels.