Figure 1.

Kirre and Rst act redundantly in patterning ommatidia. Eyes at 42 h APF were stained with an antibody against either Armadillo (A–D) or E-cadherin (E–G). (A-A’) A wild type eye. Tracing of an ommatidium is shown in (A’); inter-ommatidial cells (IOCs) are pseudo-colored in green. IR1 and IR2 indicate expression of one and two copies of indicated RNAi transgenes, respectively. IR3 refers to expression of a single copy of a transgene together with Dicer-2. Expression of all transgenes is controlled by GMR-Gal4 in this figure. (B) Strong reduction of Kirre by kirre-RNAi (kirre-IR3). Single cells failed to be selected in vertices (arrows). Occasionally bristle groups were mis-positioned (arrowhead). (C) Mild reduction of Rst by expressing a single copy of rst-RNAi (rst-IR1). An extra cell is highlighted by an arrow. (D) Expression of two copies of rst-RNAi (rst-IR2). A single cell was not selected in the vertex (arrows). Cells were often found surrounding a bristle group (arrowheads). (E) Strong reduction of Rst by rst-RNAi (rst-IR3). Defects in cone cells (arrowheads) and 1°s (asterisks) are indicated. Two ommatidia in direct contact are highlighted by double asterisks. (F) Strong reduction of both Rst and Kirre. Defects in cone cells (arrowheads) and 1°s (asterisks) are indicted. Contacting ommatidia are highlighted by double asterisks. IOCs completely failed to sort into single line. (G) Ommatidial patterning in the pupal eye does not require cell death. In hid mutants, cell death was strongly blocked and cells failed to sort into single line (arrows). However, ommatidia were separated as in wild type.