Fig. 6. Tethering of LacI-JIL-1 is not associated with upregulation of either Pol II0^ser2, Pol II0^ser5, histone H4K16 acetylation or of the BRM complex at the LacO insertion site. Triple labelings with JIL-1 antibody (in green), Pol II0^ser2 antibody (A) or Pol II0^ser5 antibody (B) (in red), and Hoechst 33258 (in blue or gray) of polytene squash preparations from larvae homozygous for the lacO repeat line P11.3. (C) Triple labeling with JIL-1 antibody (in green), histone H4K16ac antibody (in red) and Hoechst (in blue or gray) of a polytene squash preparation from a male third instar larvae homozygous for the lacO repeat line P19.9. The upregulation of histone H4K16 acetylation on the male X chromosome (X) is clearly evident in comparison to the normal autosomal level at the tethering site (arrows). (D) Triple labelings with LacI antibody (in green), Brahma antibody (in red) and Hoechst 33258 (in blue or gray) of polytene squash preparations from larvae homozygous for the lacO repeat line P11.3.