Fig. 3

Zebrafish flt4^hu4602 mutants lack the PHBC defects observed upon flt4 MO, vegfc MO or sFLT4 mRNA injection. (A-E) Angiogenesis of the primordial hindbrain channel (PHBC) fails to occur in flt4 MO-injected (5 ng/embryo) (C), sFLT4 mRNA-injected (200 pg/embryo) (D) and vegfc MO-injected (E) embryos (yellow asterisk) as compared with wild-type controls (A), but is unaffected (yellow arrow) in individually genotyped flt4^hu4602 mutants (B) at 28 hpf. (F,G) Angiogenesis of the PHBC and lymphangiogenesis respond differently to injection of flt4 MO, vegfc MO and sFLT4 mRNA. Injection of flt4 MO (5 ng/embryo) inhibits PHBC development in 29% of embryos at 28 hpf but inhibits lymphangiogenesis [thoracic duct (TD) scored as readout] with 100% efficiency at 4 dpf in the same injection (n=55 embryos scored). vegfc MO (5 ng/embryo) inhibits PHBC development in 22% of embryos (n=41) and TD development in 97% of embryos in the same injection (n=37). sFLT4 mRNA (200 pg/embryo) inhibits PHBC development in 42% of embryos and TD development in 100% of embryos in the same injection (n=120). Uninjected control embryos showed normal PHBC and TD development in 100% of cases (n=20) at 28 hpf and 4 dpf (F,G).