Fig. 8. Integrin ß1 and paxillin distribution in C3G mutant MEFs cultured without serum. Integrin ß1 (A,B,G,H) and paxillin (C,D,I,J) immunostaining of MEFs plated on laminin (A-F) or fibronectin (G-L). (E,F,K,L) Merged images with nuclear counterstain bis-benzimide. Note the punctate staining of integrin ß1 in wild-type MEFs on both substrates (B,H), which was lost in MEFs lacking normal C3G expression (A,G). In wild-type MEFs integrin ß1 focal points were also paxillin-positive. Arrowheads in B,D,F and H,J,L point to prominent examples. In contrast, C3G mutant MEFs on laminin and fibronectin exhibited an aggregation of integrin ß1 near the nucleus (A,G). Paxillin was poorly distributed in C3G mutant MEFs on laminin (C,D) and more normally distributed in mutant cells on fibronectin (I,J). A few foci of integrin ß1 and paxillin co-localisation were observed in C3G mutant MEFs (A,C,E, arrowhead). However, paxillin- and integrin ß1-positive foci were by far more numerous in the controls on both laminin (F) and on fibronectin (L). Bar represents 14 µm in all panels.