Figure 3.

Atro, dG9a and Rpd3 bind to overlapping chromosomal regions in Drosophila. A co-immunostaining experiment was performed on salivary gland cells to determine the relative positions of Atro and dG9a, Rpd3 or a marker for transcriptional initiation (RNA polymerase II-phosphorylated-Ser5 (RNAP-p-S5)) on polytene chromosomes. Salivary gland cells derived from Hsp70∷Atro late third instar larvae were subjected to co-immunostaining using (A) Atro and dG9a antibodies, (B) Atro and Rpd3 antibodies, and (C) Atro and RNAP-p-S5 antibodies. Hsp70-Gal4 is a salivary gland-specific Gal4 driver without heat-shock treatment. The enlarged images shown in the right panels of (A) correspond to the boxed area in the lower panel. Atro, Drosophila Atrophin; dG9a, the Drosophila homologue of G9a; Hsp70, Heat-shock protein 70; Rpd3, the fly homologue of histone deacetylases 1 and 2.