Fig. 6. Ephrin-Ad acts upon the notochord/neural mother cells. (A) Experimental strategy. Eggs were injected with ephrin-Ad-MO, fertilised and cultured until the late 32-cell stage, when the notochord/neural mother cells were isolated. The isolated mother cells were further cultured until the equivalent of the early gastrula stage, when they were fixed for in situ hybridisation analyses for the expression of Ci-Bra and Ci-ETR. At this stage, the resultant partial embryos consist of four cells. (B) Histograms showing the average numbers of cells positive for Ci-Bra (magenta) and Ci-ETR (blue) in partial embryos as indicated on the left of the graphs. The data are expressed as mean±s.e.m. Significant differences compared to the results obtained from the control were evaluated by the Student's t-test and indicated with asterisks (P0.01). n, total number of samples analysed.