Fig. 5. FGFA function is required in the vegetally derived tissues for skeleton formation and morphogenesis of the gut in sea urchin. (A) Experimental design. The animal and vegetal halves of wild-type (gray) and fgfA-splice morpholino-injected embryos (red) were recombined as shown. (Ba,b) Control uninjected embryos. Side views. (c-f) Chimeras in which fgfA function is inhibited in the animal half develop into pluteus larvae with reduced oral lobes and arms (arrow in e). (g-j) Inhibition of fgfA function in the vegetal half prevents skeletogenesis and disrupts gut morphogenesis.