Fig. 4. Ed protein induces homophilic cell aggregation of S2 cells. Shown are the results of a S2 cell mixing experiment, in which unlabeled and DiI-labeled S2 cells were mixed at a ratio of 1: 1 and co-aggregated. (A,B) Two views of areas with labeled and unlabeled S2 cells, which are both expressing Ed protein. The left part of each panel depicts the view using Nomarski optics, whereas the same area is shown in the right part of the panel using epifluorescence with a rhodamine filter set. In C,D, unlabeled Ed-expressing S2 cells were co-aggregated with DiI-labeled, native S2 cells. Scale bar: 70 µm.