Figure 4

DLG mutants have fewer postsynaptic glutamate receptor clusters per presynaptic active zone. A: Confocal projections of first instar NMJs visualized using three different antibodies: 1) the neuronal membrane marker anti-HRP (blue), 2) anti-GluRIID subunit antibodies which label all postsynaptic glutamate receptors (red), and 3) NC82 antibodies that label presynaptic active zones (green). Each panel shows NMJs on interior-most ventral longitudinal muscles in one hemisegment. Scale bar = 10 um. B: Number of postsynaptic glutamate receptor clusters relative to number of presynaptic active zones, showing that dlg mutants have fewer postsynaptic receptor clusters. C: High magnification images from dlg mutant NMJs showing glutamate receptor dispersion (arrows).