Cover image

Cover During the pupal stages of Drosophila eye development, the Runx homolog, lozenge (lz), regulates programmed cell death. Shown here are immunofluorescence analyses of wild-type (top) and lz-deficient pupal retinas, using antibodies directed against Armadillo to visualize the cell membranes of the cone, bristle, and pigment cells. In each image, a single ommatidium is highlighted in red. A wild-type ommatidium contains four cone cells, two 1 pigment pigment cells, nine 2/3 pigment cells, and three bristle cells. In contrast, the lz-mutant ommatidium has additional 2/3 pigment cells. (For details, see Wildonger et al., p. 1034.)