Fig. 4. Numb functions in Notch bearing cells that receive the Delta signal. (A) Control pluteus larva with pigment cells, a necessary consequence of presentation of the Delta ligand on micromeres to Notch on the receiving macromeres. (B) A pluteus larva with injected LvNumb2 morpholino. (C) The experiment in D. Micromeres bearing a LvNumb2 morpholino (red) were transplanted to a host micromereless embryo. (D) Numb morpholino in the micromeres does not affect the transfer of the Delta signal as the embryo has pigment cells. (E) Experiment in F. At the 60-cell stage, two embryos were cut in half from the animal to vegetal pole. A half bearing LvNumb2 morpholino was combined with a control half (green). (F) A fluorescent overlay shows that pigment cells produced by the control half embryo migrate into the LvNumb morpholino half embryo, indicating that if control pigment cells are provided to the Numb half they develop normally and migrate to the correct position in the ectoderm.