Fig. 4. VEGF or VEGFR loss-of-function blocks PMC spatial patterning and skeleton formation in sea urchin. Embryonic treatment (control or injected with Mo-VEGF or Mo-VEGFR) is indicated on the left of each row. In each column is shown morphology at 24 and 48 hours, expression of Ske-T at the gastrula stage and expression of MSP130 at the pluteus stage. vv, vegetal view.