Figure 2. Bmal1 or Period2 deficiency led to opposing effects on developmental angiogenesis. Transgenic fli1:EGFP zebrafish embryos expressing GFP in endothelial cells were injected with 0.2 picomole of scrambled control or specific Bmal1 or Period2 morpholino at 15 min post-fertilization. Images of the vasculature were obtained by confocal microscopy at 24-hpf, and representative images of the ISVs are shown. It is clear that Bmal1 morpholino injection lead to impaired ISV development, whereas Period2 morpholino injection lead to enhanced ISV development compared with scrambled control morpholino injected embryos. The lines indicate the height of the ISV vessels. The white scale bar is 50 μm.