Fig. 3. Non-reciprocal genome-wide dependence of E(z) on Pcl for chromosome binding. Polytene chromosomes from (A) Oregon R, (B) E(z)⁶¹, or (C) pUAST-R57-Pcl/P{GawB}c729 larvae were stained with anti-E(z) or anti-Pcl (red) and anti-IIo^Ser2 (green). (A) Wild-type distributions of E(z) and Pcl. (B) Inactivation of E(z)⁶¹ does not affect chromosome binding by Pcl. (C) Pcl knockdown results in loss of chromosome binding by E(z) (background debris signal is indicated by an arrowhead).