Fig. 1.

Schematics of Notch-mediated lateral inhibition and the lineages of five pairs of sibling cells. (A) Initially all cells within three equivalence groups acquire the potential (gray) to adopt the precursor fate. One cell (gray) is singled out as the presumptive precursor from each cluster. This cell then acts through the Notch pathway to inhibit all other cells in the group (light gray) from adopting the precursor fate, such that individual precursors cells (black) segregate from each group (right). (B) Cell lineages of the five sibling pairs assayed in this paper shown for one hemisegment of wild type, Notch/spdo or numb mutant embryos. Lineages shown in color represent those in which we follow the fate of both sibling cells. Lineages shown in black/white are those in which we use eve expression (black) to follow the fate of one of the two sibling cells in each lineage.