Fig. 4. The long form of the extracellular domain of teneurin 2 induces morphological changes and aggregation of transfected HT1080 cells. (A) Phase-contrast pictures of parental HT1080 cells and cell clones transfected with the membrane-anchored short extracellular domain (TE1) or cell clones expressing the long extracellular domain (TEY1, TEY2 and TEY3). Note that TEY-transfected cell clones show increased cell spreading and more cell-cell contacts. (B) Staining of the actin cytoskeleton by RITC-phalloidin of the cells shown in A reveals mostly cortical actin staining and no increased stress fiber formation even in the highly spread cells. (C) Phase-contrast pictures of cells dissociated by EDTA treatment and incubated in suspension on a rotary shaker for 1 hour. All clones expressing the long extracellular domain of teneurin 2 aggregated, whereas the parental cells and the cells expressing the short form of teneurin 2 remained as single cells.