Fig. 5

The LFL develops from a vascular sprout with migration, duplication, and recruitment of lymphangioblast populations to the vascular tip. (A,A′) Still images from supplementary material Movie 2 showing the developing LFL in the lyve1:EGFP;kdrl:nlsmCherry transgenic from 1.63 to 2 dpf (39 to 48 hpf). (A) lyve1 expression shows the vascular tip of the FLS, which resembles a dynamic vascular sprout with filopodia (red arrow) and lamellipodia (yellow arrow), and the migration and the recruitment of PHS lymphangioblasts (indicated by a white asterisk) to the vascular tip of the FLS. (A′) Nuclear kdrl expression shows duplication of a lymphangioblast cell (yellow and red) within the FLS (green outline), the migration of lymphangioblast cells (yellow, red, blue and beige) and the recruitment of PHS-Ls (purple outline). (B,B2) Still images from supplementary material Movie 3 showing the developing LFL in the same lyve1:EGFP;kdrl:nlsmCherry transgenic embryo as in A from 2 to 2.5 dpf (48 to 60 hpf). (B) lyve1 expression shows the migration and recruitment of another PHS-L (white asterisk) and the VA lymphangioblast (yellow asterisk) to the growing tip of the FLS to form the LFL. (B′) Nuclear kdrl expression shows duplication of lymphangioblast cells (green and light blue) within the FLS (green outline), and the migration of lymphangioblast cells from the PHS-L that have been recruited to the FLS (orange, green and light blue) to another PHS lymphangioblast (pink outline) and the VA lymphangioblast (red outline). CCV, common cardinal vein; FLS, facial lymphatic sprout; LFL, lateral facial lymphatic; PHS, primary head sinus; PHS-L, primary head sinus lymphangioblast. Scale bars: 50 μm.