Fig. 8. Binding activity and subcellular localisation of Dally and Dlp. (A-D) Transfection of Dally-HA or Dlp-HA in S2 cells causes accumulation of exogenous GFP-Wingless at the cell surface. Transfected cells are recognised with anti-HA (in A and C). HA immunoreactivity is reproducibly lower for Dally than for Dlp (compare A with C) but we do not know whether this is due to differences in expression levels or epitope accessibility. Nevertheless, Dally transfected cells reproducibly accumulate more GFP-Wingless (compare B with D). (E,F) Subcellular distribution of exogenous Dally and Dlp in wing imaginal discs. FLAG-tagged Dally expressed under the control of dpp-gal4 is present both at the cell surface and in vesicles (E), while HA-tagged Dlp is almost exclusively seen at the cell surface. Inset in E shows the detail of a disc expressing FLAG-Dally that was briefly stained with Texas Red Dextran to label the endocytic pathway. The disc was immersed live in a solution of Texas Red dextran for 10 minutes. This was followed by a 20 minute chase and subsequent fixation. Partial colocalisation of Dally (green) with dextran (red) shows that some Dally is in endocytic structures.