Figure 2.

Well-rounded is present at synapses. a, Confocal images of larval brains stained with polyclonal antibody to Wrd. Left displays a wild-type brain, and right displays a brain from an animal expressing a wrd cDNA driven pan-neuronally under elav Gal4. Wrd labeling is prominent in brain lobes and the synapse-rich region of neuropil (arrow, right). Overexpression leads to increased staining of brain lobes and cell bodies in the cortex of neuropil (arrowhead, left). b, Confocal images of muscle 4 larval NMJs costained with antibody to Wrd (green) and the neuronal marker HRP (red). Top row displays an NMJ from a wild-type animal, and bottom row is from an animal with pan-neuronal expression of Wrd under elav Gal4. Overexpression (O/E) leads to increased Wrd staining at the NMJ. c, Costaining of Wrd at wild-type NMJ with presynaptic and postsynaptic markers. Image demonstrates a single confocal slice. Left, The NMJ is stained for Wrd alone (green). Middle, The same synapse is stained for Wrd and Dlg (red), a postsynaptic marker. Right, The synapse costained with Wrd and HRP (blue), a presynaptic marker. Synaptic Wrd staining colocalizes nearly completely with HRP, as demonstrated by the increased intensity throughout the NMJ in the overlay of Wrd and HRP. Overlay of Wrd and Dlg demonstrates partial localization, because a ring of Dlg staining falls outside the Wrd staining.