Figure 2. EJC proteins accumulate at heat shock transcription puffs.
Parallel immunolocalization of hyperphosphorylated RNA Pol II Ser2 (red, II, III, V, VI, VIII, IX) and EJC proteins (green) eIF4AIII (I, III), Y14 (IV, VI), and MAGO (VII, IX), on polytene chromosomes following heat shock at 37°C for 1 hr. Yellow arrowheads indicate accumulation of EJC proteins at the induced intron-containing heat-shock genes, while white arrowheads indicate their accumulation at intronless heat-shock genes. Genes are identified by their map position (details in Results), which are labeled in the merged images on the right panels. Corresponding chromosome arms are mentioned in left column of panel. Scale bar represents 20 µm length.