English: Additional File 5 Microtubules possessing GFP-APC puncta could be seen to undergo shrinkage followed by a period of pause and then growth (arrowhead). GFP-APC puncta remained at the end of the microtubule throughout this cycle of shrinkage and growth. Of interest in this sequence is the observation that separate microtubule-associated GFP-APC puncta coalesce into a single large structure at the microtubule tip during shrinkage, then separate out into a distribution resembling beads on a string during microtubule regrowth, before beginning to re-coalesce on the paused microtubule tip at the cell periphery. Image capture was 1 frame/5s using a 63× oil immersion lens, the movie is played back at 10 frames/s.