Fig. 2. Ablation of the right side b6.5 blastomere affects A-line neural patterning. Experimental conditions are shown at the top of the panels and the marker used on the left of the panels. All embryos are in vegetal pole view. Schematic representations of embryos are shown on the left, with black dots indicating cells that express the marker and a cross indicating ablated cell descendants (in green). Lineages are shown with the same colour code as in Fig. 1. Numbers are: number of embryos with similar expression as the image/total number of embryos analysed. In all cases, the expression on the left side of the experimental embryos was positive. (A) Ci-Otx: open arrowheads indicate A7.4 blastomeres and the filled arrowhead indicates an A7.8 blastomere expressing Ci-Otx. Other expression domains are the a-line neural lineage and anterior epidermis. The insert is a control cleaving embryo. (B) Ci-Snail: 3/43 of ablated embryos showed equal expression, presumably due to failure of ablation. (C) Ci-Delta2: 1/37 of b6.5 ablated embryos showed equal expression on both sides, including b-line, probably due to failure of ablation, and was not included in the analysis. In some embryos (middle and left panel), expression can also be detected in the trunk lateral cell precursor situated between the b-line cells and the lateral A-line neural precursors. (D) Ci-ETR: among the b6.5 ablated embryos showing symmetrical expression, 5/10 had strong expression in A8.16 on both sides and 5 had weak expression on both sides. Arrowhead indicates stronger expression of Ci-ETR in A8.16 on the ablated side.