Fig. 8. Transient expression of Fyn restores cell spreading in CHO cells that express the truncated form of β3-integrin. (A) CHO cells expressing the deletion mutant IIbβ3754 were transfected with the cDNAs encoding either Fyn (top panels) or Src (bottom panels). 48 hours after transfection, cells were allowed to spread for 30 minutes in serum-free medium on coverslips coated with fibrinogen. Cells were fixed and stained with TRITC-labeled phalloidin. Cells transfected with Fyn and Src were identified by the GFP fluorescence (indicated with arrows). (B) Cells were transfected with cDNA encoding a kinase-dead version of Fyn (FynK299M) and then simultaneously stained using anti-Fyn antibodies and phalloidin. Scale bars, 20 µm.