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Fig. 7. Long-term consequences of Sf3b4 depletion on craniofacial structures formation. (A) Migration and contribution of the neural crest to cranial skeletal elements. The mandibular neural crest segment (1; yellow) contributes to Meckel’s (M), palatoquadrate (Q), and subocular (So) cartilages; the hyoid neural crest segment (2; blue) contributes to the ceratohyal (C) cartilages; the anterior (3; purple) and posterior (4; red) branchial neural crest segments contribute to the cartilages of the gills (G). Modified from Sadaghiani and Thiebaud, 1987 and Baltzinger et al., 2005. (B) By in situ hybridization sox9 is detected in the four streams of neural crest cells migrating towards the pharyngeal arches, the mandibular (ma), hyoid (hy), anterior branchial (ab) and posterior branchial (pb) segments. Lateral view, anterior to left. ey: eye; ov: otic vesicle. Modified from Lee and Saint-Jeannet, 2011. (C) Alcian blue-stained craniofacial skeletal elements from a stage 45 tadpole. Modified from O’Donnell et al., 2006. (D) At neurula stage the expression of sox10 is reduced in Sf3b4MO2-injected embryos. Dorsal views, anterior to top. The injected side (right) is indicated by the lineage tracer (Red-Gal). (E) The graph is a quantification of the results from seven independent experiments. The number of embryos analyzed (n) is indicated on the top of each bar. (F) Gross morphology of Sf3b4MO2 (5 ng) and CoMO (10 ng)-injected tadpoles. Dorsal views, anterior to top. (G) The graph is a quantification of the results from four independent experiments. The number of tadpoles analyzed (n) is indicated on the top of each bar. (*) Embryos injected with 10 ng Sf3b4MO2 did not survive to the tadpole stage. (H) Examples of flat-mounts of Alcian blue-stained skeletal elements from stage 45 tadpoles injected with Sf3b4MO2 (2 ng). Similar phenotypes were observed with 5 ng Sf3b4MO2. Injected side is on the right. (I) The graph is a quantification of the results from three independent experiments. The size of Meckel’s, ceratohyal and branchial cartilages of affected tadpoles was measured and compared to the same cartilage on the contralateral side to define the percentage reduction. Error bars indicate mean ± s.e.m. Sf3b4MO2 (2 ng), n=69 and Sf3b4MO2 (5 ng), n=38. |
