Fig. 4. EDEN-BP morpholinos alter presegmentation in the PSM. Embryos were injected in one blastomere at the two-cell stage with 25 ng of each EDEN-BP morpholino. (A-D) Lateral views of stage 25/26 embryos stained for ESR5 (A,B) or X-Delta2 (C,D). (A,C) Non-injected sides, and (B,D) injected sides of the same embryos. TBD, tailbud domain. S1 to S4, Somitomeres 1 to 4. (E-G) Posterior views of stage 20 embryos stained for ESR9, representative of phase I (E), II (F) and III (G) of the dynamic mode of expression of ESR9. (E'-G') Schematic drawings of E-G.