Fig. 5. Formation of stable microtubules in cells expressing HA1, SW1 or SßX integrin. (A,B) SW1 and SßX (SßX-ß-cyt) cells were allowed to spread on collagen IV and stained for vinculin to identify FA structures and Glu-tubulin to reveal stabilized microtubules (Glu-MT). Bar 10 µm. (C) HA1 cells and SßX cells were allowed to spread on collagen IV with or without 1% calf serum (CS) and stained with anti-₁ (anti-1) integrin to identify the HA1 and SßX integrins, and Glu-MT to reveal stabilized microtubules. Only in the presence of serum do SßX, but not SW1, cells form stable microtubules on collagen IV.