Fig. 4

Aplnr signalling modulates EC polarization.

(a-i) Confocal images of 72 h.p.f. Tg(kdrl:NLS-EGFP);Tg(fli1a:B4GALT1-mCherry) wild-type (a-c) aplnra^+/- (d-f) and aplnrb^+/- (g-i) larvae. Left panels: (a,d,g) three-dimensional (3D)-rendered confocal images of the trunk region; left centre panels: (b,e,h) 3D-rendered confocal images of the white boxed region in the left panels; right centre panels: (b′,e′,h′) 3D surface-rendered images of the centre left panels; right panels: (c,f,i) single plane images of the boxed region in the left panels. White arrowheads point to polarized ECs and yellow arrowheads point to non-polarized ECs. Yellow dashed lines denote the ventral boundary of the DA. White dashed lines denote the boundary of the DA in the single plane images. Red bars indicate the diameter of the DA. White dashed arrows denote the direction of blood flow. (j) Quantitative analysis of EC polarization in 72 h.p.f. wild type, aplnra^+/- and aplnrb^+/- larvae. The numbers of larvae (n) and ECs (n′) are indicated above the graph. ***P<0.05. (k) Design of the transplantation experiments: Tg(kdrl:NLS-EGFP);Tg(fli1a:B4GALT1-mCherry) wild type or aplnrb^+/- cells were transplanted into wild type AB hosts and the transgenic ECs in the DA scored for polarization at 72 h.p.f.. (l-o) Three-dimensional-rendered confocal images of 72 h.p.f. Tg(kdrl:NLS-EGFP);Tg(fli1a:B4GALT1-mCherry) wild-type hosts with wild-type (l,m) or aplnrb^+/- (n-o) transplanted cells. (p) Quantitative analysis of EC polarization of wild type or aplnrb^+/- cells transplanted into wild-type hosts. The numbers of larvae (n) and ECs (n′) are indicated above the graph. (q-t) Confocal images of 72 h.p.f. Tg(kdrl:NLS-EGFP);Tg(fli1a:B4GALT1-mCherry) wild type (q,r,u) and apln^-/- (s-u) larvae. The white boxes in the left panels (q,s) are enlarged in the right panels (r,t). (u) Quantitative analysis of EC polarization in 72 h.p.f. wild type and apln^-/- larvae. The numbers of larvae (n) and ECs (n′) are indicated above the graph. Anterior to the left, dorsal to the top. Scale bars, 20 µm. D, donor; DA, dorsal aorta; H, host; PCV, posterior cardinal vein. Error bars, s.e.m.