FIGURE 5

Retinal cell proliferation in cardiovascular disruption model systems. (A,C). Cryosections of doubly-transgenic (cdh5:gal4; UAS:nfsB-mCherry), DMSO-treated (DMSO Control; (A); Met-treated (Endothelial Cell-Depleted; (B); and Met-treated clutchmates (Met Control; (C) at 48 hpf, stained with anti-phosphohistone H3 (PH3; red fluorescence) and counterstained with DAPI (blue). Control retinas show numerous PH3+ profiles, particularly within apical retina (arrow in A) and the ciliary marginal zone (CMZ). Endothelial cell-depleted retinas also display apically-positioned PH3+ cells that appear to be reduced in number (B). (D,E) Cryosections of normal clutchmates (D) and sih–/– embryos (E), stained with α-PH3 and DAPI. Normal retinas show numerous PH3+ profiles while sih–/– retinas display fewer PH3+ cells. Scale bar (in A, applies to A–E) = 50 μm. (F,G) Quantification of PH3+ profiles in retinas of endothelial cell-depleted vs. control embryos (F; **p < 0.01 ANOVA with Tukey post hoc; n = 9 DMSO, 11 Met control, and 14 Endothelial cell-depleted) and sih–/– vs. normal siblings (G; **p < 0.01, Student’s t-test; n = 10 normal, 11 sih–/–).