Fig. 6. Constitutively active Rac antagonizes the ephrinA1-mediated repression of VSMC spreading. (A-B) VSMCs expressing either GFPRacN17 or GFPRacV12 cultured on tissue culture dishes coated with laminin and either Fc (A) or ephrinA1/Fc (B) were fixed 4 hours after seeding in the adhesion assay and analyzed by immunofluorescence labeling with DAPI and phalloidin-TRITC. Bar, 20 µm. (C) The morphology of GFPRacN17 (RacN17)- and GFPRacV12 (RacV12)-expressing cells cultured on tissue culture dishes coated with laminin and ephrinA1/Fc from ten randomly chosen fields were scored (spread or retracted). Data represent the mean±s.d. of three independent experiments. Non-infected cells (N.I.) in the same fields were also scored and used as a control for the ephrinA1 activity.