Fig. 3. Microtubule catastrophes do not depend on the maturation stage of focal adhesions. (A,B) A frame from a video sequence of a cell co-transfected with mCherry-paxillin (A, red) and Cerulean-zyxin (B, cyan). Paxillin marks both early (hollow arrows) and late (filled arrows) focal adhesions. Zyxin is a marker for late focal adhesions only (filled arrows). Bar, 5 µm. (C) Microtubule catastrophe ratio at early versus late adhesions. Approximately 90% of approaching microtubules undergo catastrophe both at early and late adhesions. A total of 117 catastrophe events in four cells were quantified.