Localization of Nub protein in immunocompetent tissues of flies. (A,B) Immunostaining of Nub in frozen cryostat sections of uninfected OrR flies using a peptide-specific antibody directed against a common epitope of Nub-PB and Nub-PD protein. Nuclei stained with 4′-6-diamidino-2-phenylindole (DAPI) (A′-B′). Cryostat sections (20 μm thick) of adults showing nuclear (arrows) and cytoplasmic and staining of Nub in fat body tissue (A,A′) and in cross-sections of midgut (B,B′). Scale bars, 100 μm.