(A) Wild-type mid-pupal eye stained with α-Arm. The interommatidial lattice in wild-type eyes is virtually error-free. 1°, 2°, 3°: primary, secondary, and tertiary pigment cells, respectively; cc: cone cells. Bristles cells appear as white circles in these preparations. zipEbr/zip02957 (B) and sev>zipDN (C) mid-pupal eyes stained with α -Arm. Multiple patterning defects arise when Zip function is decreased. See text for details.