Figure 6

Figure 6. Acting in opposition to osr1, hand2 inhibits wnt2ba-driven podocyte development (A–C) Embryos from ocn incrosses were injected with hand2 MO. Podocyte area and cell number were partially rescued in ocn−/− injected embryos and were expanded in WT injected siblings. This signified that hand2 suppresses podocyte formation. (D,E) Similarly, wnt2ba expression was rescued in osr1/hand2 morphants compared with uninjected WT controls. Injection of hand2 MO alone led to a significant increase in the wnt2ba domain. All images were at 24 hpf, scale bar is 30 μm. A minimum of 5 individuals were imaged for quantification. p-values: ** p < 0.001, * p < 0.05, N.S. = not significant. (F) osr1 promotes podocyte and kidney lineages and suppress blood and vasculature, while hand2 acts in opposition. Imbalance of either of these factors leads to changes in mesodermal fates. Podocyte development is one example of a mesodermal fate that is altered by imbalance of osr1/hand2. This is because the downstream factor wnt2ba is decreased without osr1 yet increased in the absence of hand2. wnt2ba endorses the podocyte factor wt1a/b, which has been shown to be required for formation of podocytes and the slit diaphragm (nphs1).