Fig. 4. Inca is required to form the NC-derived head skeleton in both frog and fish. (A) Western blot analysis showing that Xenopus Inca MOs efficiently inhibit translation of injected Inca-GFP mRNA. (B-I) Stage 45 Xenopus tadpoles injected with control MO (B,D,F) or Inca MO (C,E,G) and shown in dorsal (B,C) and ventral (D-I) views either live (B-E) or stained with Alcian Blue for cartilage (F-I). Similar results were obtained with two independent, non-overlapping sets of Inca MOs (H, 20 ng control MO; I, 20 ng IncaA MO2+IncaB MO2). (J-O) 5-day-old control zebrafish larvae (J,L,N) or inca1 MO morphants (K,M,O) shown live in lateral view (J,K) or Alcian Blue-stained in ventral view (L-O). All cartilage elements are reduced by Inca knockdown in both species. ba, basihyal; br, branchial/gills; cb, ceratobranchial; ch, ceratohyal; ep, ethmoid plate; hs, hyosymplectic; m, Meckel's; nc, notochord; pq, palatoquadrate; t, trabeculae. (P) Frequency of head cartilage phenotype with Xenopus IncaA MO or IncaB MO alone or combined IncaA+IncaB, and Zebrafish inca1-MO injected embryos.