title: Sister chromatid resolution is an intrinsic part of chromosome organization in prophase.
abstract: The formation of mitotic chromosomes requires both compaction of chromatin and the resolution of replicated sister chromatids. Compaction occurs during mitotic prophase and prometaphase, and in prophase relies on the activity of condensin II complexes. Exactly when and how sister chromatid resolution occurs has been largely unknown, as has its molecular requirements. Here, we established a method to visualize sister resolution by sequential replication labelling with two distinct nucleotide derivatives. Quantitative three-dimensional imaging then allowed us to measure the resolution of sister chromatids throughout mitosis by calculating their non-overlapping volume within the whole chromosome. Unexpectedly, we found that sister chromatid resolution starts already at the beginning of prophase, proceeds concomitantly with chromatin compaction and is largely completed by the end of prophase. Sister chromatid resolution was abolished by inhibition of topoisomerase IIα and by depleting or preventing mitotic activation of condensin II, whereas blocking cohesin dissociation from chromosomes had little effect. Mitotic sister chromatid resolution is thus an intrinsic part of mitotic chromosome formation in prophase that relies largely on DNA decatenation and shares the molecular requirement for condensin II with prophase compaction.
authors.affiliation: Cancer Institute of the Japanese Foundation for Cancer Research, Division of Experimental Pathology, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550, Japan.|Tokyo Institute of Technology, Department of Biological Sciences, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Nagasaka
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: M Julius
authors.identifier: 0000-0003-3303-5755
authors.initials: MJ
authors.lastname: Hossain
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: M Julia
authors.initials: MJ
authors.lastname: Roberti
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Ellenberg
authors.affiliation: Cancer Institute of the Japanese Foundation for Cancer Research, Division of Experimental Pathology, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Hirota
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000378:metabolism; D002460:Cell Line; D002842:Chromatids / Q000378:metabolism*; D004261:DNA Replication / Q000502:physiology; D004250:DNA Topoisomerases, Type II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008938:Mitosis / Q000502:physiology*; D046912:Multiprotein Complexes / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D049468:Prometaphase / Q000502:physiology*; D011418:Prophase / Q000502:physiology*
chemical_list: D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; C108312:condensin complexes; D000251:Adenosine Triphosphatases; D004250:DNA Topoisomerases, Type II