Fig. 4. DEph binds to Dephrin. (A) Drosophila S2 cells were incubated with medium derived from cell cultures expressing the extracellular part of DEph fused to GFP at the C terminus (DEphex-GFP). Owing to the endogenous expression of Dephrin, DEphex-GFP in the medium binds to the surface of untreated S2 cells (control) and the cells can be stained with -GFP. (B) Lowering the expression of Dephrin by incubating S2 cells with dsDephrin RNA (Dephrin RNAi) abolishes the binding of DEphex-GFP, confirming the specificity of the binding. (C) Control incubation of S2 Cells with dsDEph RNA (DEph RNAi) does not interfere with the binding of DEphex-GFP.