TY - JOUR TI - Super-resolution kinetochore tracking reveals the mechanisms of human sister kinetochore directional switching AU - Burroughs, Nigel J AU - Harry, Edward F AU - McAinsh, Andrew D A2 - Hyman, Anthony A VL - 4 PY - 2015 DA - 2015/10/13 SP - e09500 C1 - eLife 2015;4:e09500 DO - 10.7554/eLife.09500 UR - https://doi.org/10.7554/eLife.09500 AB - The congression of chromosomes to the spindle equator involves the directed motility of bi-orientated sister kinetochores. Sister kinetochores bind bundles of dynamic microtubules and are physically connected through centromeric chromatin. A crucial question is to understand how sister kinetochores are coordinated to generate motility and directional switches. Here, we combine super-resolution tracking of kinetochores with automated switching-point detection to analyse sister switching dynamics over thousands of events. We discover that switching is initiated by both the leading (microtubules depolymerising) or trailing (microtubules polymerising) kinetochore. Surprisingly, trail-driven switching generates an overstretch of the chromatin that relaxes over the following half-period. This rules out the involvement of a tension sensor, the central premise of the long-standing tension-model. Instead, our data support a model in which clocks set the intrinsic-switching time of the two kinetochore-attached microtubule fibres, with the centromeric spring tension operating as a feedback to slow or accelerate the clocks. KW - mitosis KW - kinetochore KW - chromosome segregation KW - microtubule KW - cell division KW - chromatin JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -