Fig. 3. LjPax6 expression in developing embryos of L. japonica using whole-mount in situ hybridization. Lateral (A-E,G) and ventral (F,H) views. Anterior is towards the left in all the embryos. (A) LjPax6 expression at stage 19. The weak expression in the anterior neural tube is indicated by a white arrowhead. (B) Stage 20. Transcripts are detected in the anterior neural tube and hindbrain (black arrowhead). (C) Stage 21. Expression is restricted to the rostral hindbrain (black arrowhead) and no transcripts are seen in the posterior hindbrain (black arrow). (D) Stage 22. LjPax6 expression is detected in the forebrain and the spinal cord. The part of the hindbrain that corresponds to r4 is devoid of LjPax6 expression (black arrow). (E,F) Stage 23. Forebrain expression is intensified. Transcripts are also detected in the dorsal oral ectoderm (arrow in F). (G,H) Stage 24. LjPax6 transcripts appear in the optic vesicle (white arrow), the ectoderm behind the optic vesicle (arrowhead) and the dorsal oral ectoderm (arrow in H). LjPax6 is weakly expressed in r4 (arrow in G).