Figure 3. ESRRa regulates development of neural crest cells for cartilage development.

(A–J) Embryos at 1-cell stage were injected with either MOctrl or MOesrra and analysed for expression of dlx2a or dhand by in situ hybridization. Expression of dlx2a at 24 hpf shows a similar pattern between control and MOesrra-injected embryos while expression of both dlx2a and dhand at 30 hpf shows a slight decrease in the branchial arches (white arrows in D and F) in MOesrra-injected embryos. From 2 dpf to 3 dpf, expression of dlx2a becomes largely restricted to pharyngeal cartilage in control embryos (arrows in I), while it is significantly disorganised in the pharyngeal arches of MOesrra-injected embryos (arrow in J). (K–N) Expression of myod from 2 dpf to 3 dpf shows a significant change as the pharyngeal regions in control embryos undergo growth and differentiation (compare K to M). However, expression of myod at 3 dpf remains strikingly similar to that at 2 dpf (compare L and N), except few additional elements being developed in MOesrra-injected embryos. Embryos are shown in either lateral (A–J) or ventral views (K–N).