Fig. 7. Immunocytochemical and immunoblot labeling of Pol IIo^ser2 in JIL-1 null mutant backgrounds. (A) Robust Pol IIo^ser2 antibody labeling (green) of chromosomes including the male X chromosome (X) in polytene chromosome squash preparations from JIL-1^z2/JIL-1^z2 (z2) and JIL-1^z2/JIL-1^z2 Su(var)3-9⁰⁶ (z2, 3-9) third instar Drosophila larvae. The DNA (blue/gray) was labeled by Hoechst. (B) Immunoblot of protein extracts from wild-type (wt), JIL-1^z2/JIL-1^z2 (z2), and JIL-1^z2/JIL-1^z2 Su(var)3-9⁰⁶ (z2, 3-9) larvae labeled with Pol IIo^ser2 antibody. Labeling with lamin antibody was used as a loading control.