Fig. 3. Tethering of LacI-JIL-1 to heterozygous lacO repeat insertion lines. (A-C) Polytene squash preparations double labeled with JIL-1 antibody (green) and either Hoechst 33258 or propidium iodide (red or gray). Heterozygous preparations for the band insertion line P11.3 (A), the band-interband insertion line P19.9 (B) and the interband insertion line 4D5 (C) are shown. (D) Heterozygous preparation for the interband insertion line 4D5 triple labeled with LacI antibody in green, H3S10ph antibody in red and with Hoechst 33258 labeling of DNA in blue or gray. Arrowheads in B,C point to bands of compacted chromatin that are decondensed on the polytene chromosome half where LacI-JIL-1 was targeted. A tub-GAL4 driver was used in A-D.