Fig. 1. Microtubule catastrophes at focal adhesions (FA) are specific events. (A,B) Kymographs of microtubule dynamics at focal adhesions (A) and in adhesion-free cytoplasm (B). Upper panels show 3xGFP-EMTB (green), mCherry-paxillin (red) and microtubule life-history plot (white line); catastrophes at adhesions (arrows) and a catastrophe in an adhesion-free area (arrowhead) are indicated. Lower panels show microtubule images only. Microtubule shrinkage of 0.5 µm or more is considered to be a catastrophe. (C) Frame from a TIRF video sequence of fish fibroblasts co-transfected with 3xGFP-EMTB (green) to visualize microtubules and mCherry-paxillin (red) to mark focal adhesions. Bar, 10 µm. The boxed region is presented in the kymograph in A. (D) Microtubule catastrophe distribution in the ventral cell layer. A total of 292 catastrophes were quantified in five 3xGFP-EMTB- and mCherry-paxillin-co-transfected cells within 12 minutes. (E) The average microtubule elongation per catastrophe is reduced by a factor of seven at focal adhesions (blue, 0.71 µm/catastrophe) compared with elsewhere (red, 4.91 µm/catastrophe). A total of 24 microtubules were quantified in five 3xGFP-EMTB- and mCherry-paxillin-co-transfected cells within 12 minutes. Error bars are ± s.d.