Syt VII–YFP colocalizes with peripheral domains of late endosomes/lysosomes. (A) BMMs were transduced with Syt VII–YFP, fixed, and stained with anti-Lamp1 mAbs. (B) BMMs were transduced with Syt VII–YFP, and the lysosomal compartment was loaded with rhodamine B–dextran before fixation. (A and B) Images are sequential 0.8-μm optical slices of a confocal z stack. (C) BMMs were transduced with Syt VII–YFP and CFP-CD63 and examined by live confocal microscopy. (A–C) The arrows point to domains enriched in Syt VII–YFP that were closely associated with Lamp1-positive compartments (A), rhodamine B–dextran-containing compartments (B), or compartments containing CFP-CD63 (C). (D) BMMs were transduced with Syt VII–YFP, and early endosomes were loaded with AlexaFluor555-transferrin before fixation. Images are sequential 0.8-μm optical slices of a confocal z stack. Arrows point to compartments containing Syt VII–YFP or AlexaFluor555-transferrin that are not in close association with each other. Arrowheads point to a cluster of Syt VII–enriched domains that are not associated with transferrin-containing early endosomes. Bars, 5 μm.