Abbreviations 16 MT: microtubule 17 kMT: kinetochore microtubule 18 cryo-ET: electron cryotomography / cryo-electron tomography 19 20 Running title: Cryo-ET of the yeast mitotic machinery in vivo 21 1 ABSTRACT 22 In dividing cells, depolymerizing spindle microtubules move chromosomes by pulling at 23 their kinetochores. While kinetochore subcomplexes have been studied extensively in 24 563 Yong for advice on chromatography, the Jensen lab for computer access, and members 564 of the Gan group, Jack Johnson, Steve Harrison and Paul Matsudaira for feedback. 565 CTN, CC, LD, and LG were funded by NUS startups R-154-000-515-133, R-154-000-566 524-651, and D-E12-303-154-217, an MOE T2 R-154-000-624-112, with equipment 567 support from NUS YIA R-154-000-558-133. HHL and US were funded by the 568 Biomedical Research Council of A*STAR (Agency of Science Technology and 569 Research), Singapore. 570 571 Contributions 572 CTN -experiments, project design, writing, LD -experiments, CC -project design, 573 experiments, HHL -experiments, JS -training, US -project design, writing, LG -574 experiments, project design, writing.575