Fig. 5. Polytene chromosome labeling by three different H3S10ph antibodies in response to heat shock treatment in JIL-1 null mutants. Acid-free polytene chromosome squash preparations from female JIL-1^z2/JIL-1^z2 third instar Drosophila larvae triple labeled with antibodies to Pol IIo^ser2 (green), H3S10ph (red), and with Hoechst (DNA, blue/gray) after heat shock treatment. H3S10ph labeling by antibodies from Cell Signaling, Epitomics and Upstate. Arrows indicate the likely position of the 87A/C heat shock puff regions.