Fig. 5. Ci-Delta2 expression at the 64-cell stage is a target of Nodal signalling. (A-C) Embryo treatment is indicated above the panels. n=total number of embryos analysed. (A) Expression of Ci-Delta2 at the 64-cell stage. The expression pattern is represented by schematic drawings on the right of each embryo panel. Ci-Delta2 is expressed in A7.8 (orange), A7.6 (mauve) and b7.10/b7.9 (green). On the schematic drawings, the secondary notochord precursor is marked by a blue dot. The graph shows the percentage of embryos (y-axis) showing expression in at least one blastomere for each of the different lineages (indicated by the colour scheme), following the treatment shown on the x-axis. (B) A graph showing the percentage of embryos (y-axis) in which Ci-Delta2 expression was detected in the different lineages on the left-(L) or right-(R) hand sides on the embryo following the treatments indicated on the x-axis. The colour scheme is the same as in A. Consistent with the observation that Ci-Bra and Ci-Nodal was sometimes recovered following b5.3 ablation, we observed expression of Ci-Delta2 in the trunk lateral cell precursor on the ablated side in 11% of embryos when analysed at the 76-cell stage (n=53). (C) A representative embryo for each of the treatments shown in B.