Slob expression at the Drosophila NMJ. HRP antibody stains nerve surface and presynaptic terminals (red; left column). White arrows in A point to individual synaptic boutons. Polyclonal antibody to Slob (green; middle column) stains Slob in nerve and nerve terminals and to a more limited extent in muscle. Overlay (yellow-orange; right column) illustrates colocalized Slob and HRP staining. (A) Staining of the WT line in the absence of primary antibody to Slob. (B) Staining of the WT line. (C) Staining of the Slob-null line. Bar, 5 µm.