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Fig. 7
Signaling through Flt4 Y1226/7 is dispensable for facial lymphatic formation and function. (A-F) Confocal images of Tg(fli1a:egfp)y1 embryos at 36 hpf of the indicated genotype immunostained with antibodies against Prox1 in red and GFP in green. (A-C) Arrowheads denote Prox1-positive endothelial cells in facial lymphatic sprout (FLS) emerging from the common cardinal vein (CCV, indicated by an arrow). (D-F) Prox1-positive endothelial cells within primary head sinus (PHS, indicated by an arrow) at 36 hpf denoted by arrowheads. (G) Quantification of Prox1-positive cells from the CCV at 36 hpf; ns, not statistically significant; error bars are ±s.d. (H-K) Confocal images of live Tg(lyve1b:dsRed2)nz101 embryos of the indicated genotype at 4 dpf; pseudocoloring is based on depth: red is surface, green and blue are deeper. Lateral facial lymphatic (LFL), otolithic lymphatic vessel (OLV), posterior cerebral vein (PCeV) and forming lymphatic aortic arches (LAA) are indicated. Arrowhead denotes dorsal wall of the primary head sinus (PHS), which is pseudocolored green. Arrows indicated by asterisks denote stunted LFL. (A-F,H-K) Lateral views, anterior to the left, dorsal is up. (L) Percentage of embryos of the indicated genotype with FLV formation. Numbers of embryos scored in each category are indicated; ***P<0.001; ns, not significant. (M-Q) Dorsal views, anterior to the left. (M-M‴) Live wild-type Tg(fli1a:egfp)y1;(gata1:dsRed2)sd2 embryo at 4 dpf subjected to microangiography with Qdots655 (gray). Arrows denote Qdot perfusion of FLV, bracket indicates PHS lumen. (N-Q) Confocal images of live Tg(fli1a:egfp)y1 embryos at 4 dpf of the indicated genotype subjected to microangiography with Qdots655 (red). Arrows denote FLV, bracket indicates the lumen of the PHS.