The Vegfc/Flt4 pathway is affected in zebrafish hhex mutants. a?d Whole-mount in situ hybridization showing flt4 (a, b) and vegfc (c, d) expression in 24?hpf hhex+/+ and hhex?/? embryos. At 24?hpf, hhex mutants exhibit decreased flt4 expression (asterisks), whereas vegfc expression in the PCV appears to be slightly increased (arrowheads). e?h Whole-mount in situ hybridization showing flt4 (e, f) and vegfc (g, h) expression at 32?hpf in hhex+/+ and hhex?/? embryos. At 32?hpf, hhex mutants exhibit a strong decrease in flt4 expression (asterisks), whereas vegfc expression is clearly increased in the PCV (arrowheads). x/y: number of embryos showing representative phenotype (x), number of embryos examined (y). i Trunk vasculature of 5?dpf Tg(kdrl:EGFP); hhex?/? injected, or not, with full-length human FLT4 mRNA. hhex mutants exhibit partial rescue of their vISVs at 5?dpf (arrowheads point to vISVs). j Quantification of vISVs across 10 somites in 5?dpf non-injected hhex?/? (n?=?6) and FLT4 mRNA-injected hhex?/? (n?=?8). k Trunk lymphatic vasculature of 5?dpf Tg(?5.2lyve1b:DsRed); hhex?/? injected, or not, with full-length human FLT4 mRNA. hhex mutants exhibit partial rescue of their TD at 5?dpf (arrowheads point to vISVs and arrow points to TD). l Quantification of TD extensions across 10 somites in 5?dpf non-injected hhex?/? (n?=?6) and FLT4 mRNA-injected hhex?/? (n?=?7). Values represent means?±?s.e.m. ****P???0.0001 and *P???0.05 by t-test. Scale bars: 50??m
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