Fig. 6. Sox9 depletion leads to a loss of neural crest progenitors and an expansion of neural tissues. (A) Embryos were injected in one blastomere at the two-cell stage with 10 ng of Sox9-AS or Co-AS and analyzed by whole-mount in situ hybridization at stage 17-19 (Snail, Pax3, Nrp1 and Sox2) or stage 23 (Twist). Dorsal view, anterior is at the top. RNA encoding the lineage tracer ß-galactosidase was co-injected to identify the injected side (red staining), the right side in all panels. Upon injection of Sox9-AS, expression of the neural crest markers Twist, Snail and Pax3 are greatly reduced, while expression of the pan-neural marker Nrp1 and Sox2 is expanded. Expression of the same markers in Co-AS-injected embryos is presented for comparison. (B) Tissue sections of representative Sox9-AS-injected embryos stained for Slug or Sox2 expression. Injected side is on the right. n, notochord; s, somite.
