Whole-mount immunostaining of the vascular bed by CD31 and apoptotic cells by cleaved caspase-3 in the retinae at P5 8 h after intravitreal injection of Sema3C or IgG-Fc. Representative images show active caspase-3 signals that co-localize with endothelial cells (arrows). Scale bar, 100 μm.Quantification of cleaved caspase-3 normalized to area of CD31-stained vessels (mean ± s.e.m; n = 5; **P = 0.007 using paired Student's t-test). 