Defective hindbrain angiogenesis in bbhm292 mutants. (A) At 48 hpf, a lateral view of the hindbrain of the wild type embryo shows central arteries (CtA, red arrows) sprouting from posterior communicating segment (PCS) and basilar artery (BA) and draining into primordial hindbrain channel (PHBC) (B) At 72 hpf, the CtAs penetrate deeply into the hindbrain in wild type embryos (red double-headed arrow). (C) 48 hpf bbh homozygous mutants show a reduced number and atypical growth direction of the CtAs (yellow arrows). (D) At 72 hpf, the CtAs in bbh homozygotes invade into the hindbrain matter, but have reduced length as compared to wild type embryos (yellow double-headed arrow). (E) In a dorsal view regular, lumenized CtA are observed in 48 hpf wild type embryos. (F) At 72 hpf, the basic network structure of the CtA remains similar, although is more refined. (G) In contrast, 48 hpf bbh homozygotes show a reduced number of CtAs, with very irregular morphology (yellow arrowhead). (H) At 72 hpf, the structure of CtA vasculature in bbh homozygotes has an irregular morphology with abnormal connections and irregular vessel size. (I) Quantitation of the percentage normal CtAs at 48, 72 and 96 hpf in wild type embryos (wt) and bbh homozygotes (bbh).
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