Figure 3

Figure 3. Amputation-mediated Notch signaling regulates EC proliferation in the DLAV and CVP during vascular loop formation. (A) DAPT treatment to inhibit Notch activity significantly reduced the number of EC proliferation (pHH3⁺EC, green) compared to DMSO-treated controls at 2 dpa (white arrowheads). Scale bar: 20 μm. (B) Gata1a MO injection or BDM treatment reduced, whereas epo mRNA and isoproterenol treatment increased pHH3⁺ EC at 2 dpa. (^*p< 0.05, ^**p< 0.005, ^***p< 0.0005 vs. control MO, n = 5 for each group). Scale bar: 20 μm. (C) Total numbers of endothelial pHH3⁺ EC in posterior tail segment and the caudal SeA were assessed to quantify Notch-dependent proliferation. 2 days of DAPT treatment resulted ~48% reduction in total number of pHH3⁺ EC, but not in the caudal SeA (^**p< 0.005 vs. DMSO, n = 3 for DMSO, n = 5 per other groups). (D) Schematic representation of Notch-mediated pHH3⁺ EC during vascular loop formation. (E) Total pHH3⁺ EC in posterior tail were assessed to quantify WSS-dependent EC proliferation. Gata1a MO injection or BDM treatment reduced ~42 and ~65%, whereas epo mRNA and isoproterenol treatment increased pHH3⁺ EC by ~52 and ~39% respectively at 2 dpa. (^*p< 0.05, ^**p< 0.005, ^***p< 0.0005 vs. control MO, n = 5 for each group). Scale bar: 20 μm.