Fig. 6.

Late hypoxia affects skeletal structure but not skeletal patterning. (A-F) Representative images of live embryos: normoxic embryos are presented in the upper row and equivalently staged hypoxic embryos are on the bottom. (A,B) Embryos at early gastrula stage show similar morphology in normoxia and hypoxia. (C,D) A hypoxic embryo at late gastrula stage shows two spicules with ectopic spicule branching (D) that are not observed in the normoxic embryo (C). Inset shows the outlined area at higher magnification. (E,F) Embryos at pluteus stage. Arrowhead in F indicates an abnormal spicule growing in the hypoxic embryo. (G) Quantification of late hypoxia experiment over three biological replicates. Color code is indicated in the representative images. Error bars indicates s.d. of three independent biological repeats. (H-K) WMISH results of nodal, BMP2/4, VEGF and VEGFR at early gastrula stage. A normoxic embryo is presented at the top and a hypoxic embryo is at the bottom of each panel. On the bottom right of each figure, the number of embryos that show this expression pattern out of all embryos scored is provided, based on three independent biological replicates.