Logo of jcellbiolHomeThe Rockefeller University PressEditorsContactInstructions for AuthorsThis issue
J Cell Biol. 1995 Oct 1; 131(1): 7–17.
PMCID: PMC2120606

A postprophase topoisomerase II-dependent chromatid core separation step in the formation of metaphase chromosomes


Metaphase chromatids are believed to consist of loops of chromatin anchored to a central scaffold, of which a major component is the decatenatory enzyme DNA topoisomerase II. Silver impregnation selectively stains an axial element of metaphase and anaphase chromatids; but we find that in earlier stages of mitosis, silver staining reveals an initially single, folded midline structure, which separates at prometaphase to form two chromatid axes. Inhibition of topoisomerase II prevents this separation, and also prevents the contraction of chromatids that occurs when metaphase is arrested. Immunolocalization of topoisomerase II alpha reveals chromatid cores analogous to those seen with silver staining. We conclude that the chromatid cores in early mitosis form a single structure, constrained by DNA catenations, which must separate before metaphase chromatids can be resolved.

Full Text

The Full Text of this article is available as a PDF (2.5M).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Adachi Y, Luke M, Laemmli UK. Chromosome assembly in vitro: topoisomerase II is required for condensation. Cell. 1991 Jan 11;64(1):137–148. [PubMed]
  • Boy de la Tour E, Laemmli UK. The metaphase scaffold is helically folded: sister chromatids have predominantly opposite helical handedness. Cell. 1988 Dec 23;55(6):937–944. [PubMed]
  • Buchenau P, Saumweber H, Arndt-Jovin DJ. Consequences of topoisomerase II inhibition in early embryogenesis of Drosophila revealed by in vivo confocal laser scanning microscopy. J Cell Sci. 1993 Apr;104(Pt 4):1175–1185. [PubMed]
  • Clarke DJ, Johnson RT, Downes CS. Topoisomerase II inhibition prevents anaphase chromatid segregation in mammalian cells independently of the generation of DNA strand breaks. J Cell Sci. 1993 Jun;105(Pt 2):563–569. [PubMed]
  • Cook PR. The nucleoskeleton and the topology of replication. Cell. 1991 Aug 23;66(4):627–635. [PubMed]
  • Denton TE, Brooke WR, Howell WM. A technique for the simultaneous staining of both nucleolar organizer regions and kinetochores of human chromosomes with silver. Stain Technol. 1977 Nov;52(6):311–313. [PubMed]
  • DiNardo S, Voelkel K, Sternglanz R. DNA topoisomerase II mutant of Saccharomyces cerevisiae: topoisomerase II is required for segregation of daughter molecules at the termination of DNA replication. Proc Natl Acad Sci U S A. 1984 May;81(9):2616–2620. [PMC free article] [PubMed]
  • Downes CS, Unwin DM, Northfield RG, Berry MJ. Automatic nitrous oxide synchronization of mitotic human cell cultures. Anal Biochem. 1987 Aug 15;165(1):56–58. [PubMed]
  • Downes CS, Clarke DJ, Mullinger AM, Giménez-Abián JF, Creighton AM, Johnson RT. A topoisomerase II-dependent G2 cycle checkpoint in mammalian cells/. Nature. 1994 Dec 1;372(6505):467–470. [PubMed]
  • Earnshaw WC, Heck MM. Localization of topoisomerase II in mitotic chromosomes. J Cell Biol. 1985 May;100(5):1716–1725. [PMC free article] [PubMed]
  • Earnshaw WC, Laemmli UK. Silver staining the chromosome scaffold. Chromosoma. 1984;89(3):186–192. [PubMed]
  • Earnshaw WC, Halligan B, Cooke CA, Heck MM, Liu LF. Topoisomerase II is a structural component of mitotic chromosome scaffolds. J Cell Biol. 1985 May;100(5):1706–1715. [PMC free article] [PubMed]
  • Gasser SM, Laemmli UK. The organisation of chromatin loops: characterization of a scaffold attachment site. EMBO J. 1986 Mar;5(3):511–518. [PMC free article] [PubMed]
  • Goodpasture C, Bloom SE. Visualization of nucleolar organizer regions im mammalian chromosomes using silver staining. Chromosoma. 1975 Nov 20;53(1):37–50. [PubMed]
  • Gorbsky GJ. Cell cycle progression and chromosome segregation in mammalian cells cultured in the presence of the topoisomerase II inhibitors ICRF-187 [(+)-1,2-bis(3,5-dioxopiperazinyl-1-yl)propane; ADR-529] and ICRF-159 (Razoxane). Cancer Res. 1994 Feb 15;54(4):1042–1048. [PubMed]
  • Hirano T, Mitchison TJ. Cell cycle control of higher-order chromatin assembly around naked DNA in vitro. J Cell Biol. 1991 Dec;115(6):1479–1489. [PMC free article] [PubMed]
  • Hirano T, Mitchison TJ. Topoisomerase II does not play a scaffolding role in the organization of mitotic chromosomes assembled in Xenopus egg extracts. J Cell Biol. 1993 Feb;120(3):601–612. [PMC free article] [PubMed]
  • Holm C. Coming undone: how to untangle a chromosome. Cell. 1994 Jul 1;77(7):955–957. [PubMed]
  • Holm C, Stearns T, Botstein D. DNA topoisomerase II must act at mitosis to prevent nondisjunction and chromosome breakage. Mol Cell Biol. 1989 Jan;9(1):159–168. [PMC free article] [PubMed]
  • Homberger HP. Bent DNA is a structural feature of scaffold-attached regions in Drosophila melanogaster interphase nuclei. Chromosoma. 1989 Aug;98(2):99–104. [PubMed]
  • Howell WM, Hsu TC. Chromosome core structure revealed by silver staining. Chromosoma. 1979 Jun 21;73(1):61–66. [PubMed]
  • Jan KY, Tzeng YJ, Lee TC. Opposite staining effect of two silver-staining techniques on sister chromatids. Exp Cell Res. 1985 Jul;159(1):55–62. [PubMed]
  • Johnson RT, Rao PN. Mammalian cell fusion: induction of premature chromosome condensation in interphase nuclei. Nature. 1970 May 23;226(5247):717–722. [PubMed]
  • Koshland D, Hartwell LH. The structure of sister minichromosome DNA before anaphase in Saccharomyces cerevisiae. Science. 1987 Dec 18;238(4834):1713–1716. [PubMed]
  • Laemmli UK, Käs E, Poljak L, Adachi Y. Scaffold-associated regions: cis-acting determinants of chromatin structural loops and functional domains. Curr Opin Genet Dev. 1992 Apr;2(2):275–285. [PubMed]
  • Lawrence JB, Singer RH, McNeil JA. Interphase and metaphase resolution of different distances within the human dystrophin gene. Science. 1990 Aug 24;249(4971):928–932. [PubMed]
  • Ma X, Saitoh N, Curtis PJ. Purification and characterization of a nuclear DNA-binding factor complex containing topoisomerase II and chromosome scaffold protein 2. J Biol Chem. 1993 Mar 25;268(9):6182–6188. [PubMed]
  • Mirkovitch J, Mirault ME, Laemmli UK. Organization of the higher-order chromatin loop: specific DNA attachment sites on nuclear scaffold. Cell. 1984 Nov;39(1):223–232. [PubMed]
  • Mullinger AM, Johnson RT. The organization of supercoiled DNA from human chromosomes. J Cell Sci. 1979 Aug;38:369–389. [PubMed]
  • Negri C, Scovassi AI, Braghetti A, Guano F, Astaldi Ricotti GC. DNA topoisomerase II beta: stability and distribution in different animal cells in comparison to DNA topoisomerase I and II alpha. Exp Cell Res. 1993 May;206(1):128–133. [PubMed]
  • Newport J, Spann T. Disassembly of the nucleus in mitotic extracts: membrane vesicularization, lamin disassembly, and chromosome condensation are independent processes. Cell. 1987 Jan 30;48(2):219–230. [PubMed]
  • Ochs RL, Busch H. Further evidence that phosphoprotein C23 (110 kD/pI 5.1) is the nucleolar silver staining protein. Exp Cell Res. 1984 May;152(1):260–265. [PubMed]
  • Paulson JR, Laemmli UK. The structure of histone-depleted metaphase chromosomes. Cell. 1977 Nov;12(3):817–828. [PubMed]
  • Pillidge L, Downes CS, Johnson RT. Defective post-replication recovery and u.v. sensitivity in a simian virus 40-transformed Indian muntjac cell line. Int J Radiat Biol Relat Stud Phys Chem Med. 1986 Jul;50(1):119–136. [PubMed]
  • Rattner JB, Lin CC. Radial loops and helical coils coexist in metaphase chromosomes. Cell. 1985 Aug;42(1):291–296. [PubMed]
  • Roca J, Ishida R, Berger JM, Andoh T, Wang JC. Antitumor bisdioxopiperazines inhibit yeast DNA topoisomerase II by trapping the enzyme in the form of a closed protein clamp. Proc Natl Acad Sci U S A. 1994 Mar 1;91(5):1781–1785. [PMC free article] [PubMed]
  • Rowley R, Kort L. Novobiocin, nalidixic acid, etoposide, and 4'-(9-acridinylamino)methanesulfon-m-anisidide effects on G2 and mitotic Chinese hamster ovary cell progression. Cancer Res. 1989 Sep 1;49(17):4752–4757. [PubMed]
  • Saitoh N, Goldberg IG, Wood ER, Earnshaw WC. ScII: an abundant chromosome scaffold protein is a member of a family of putative ATPases with an unusual predicted tertiary structure. J Cell Biol. 1994 Oct;127(2):303–318. [PMC free article] [PubMed]
  • Saitoh Y, Laemmli UK. Metaphase chromosome structure: bands arise from a differential folding path of the highly AT-rich scaffold. Cell. 1994 Feb 25;76(4):609–622. [PubMed]
  • Sedat J, Manuelidis L. A direct approach to the structure of eukaryotic chromosomes. Cold Spring Harb Symp Quant Biol. 1978;42(Pt 1):331–350. [PubMed]
  • Shamu CE, Murray AW. Sister chromatid separation in frog egg extracts requires DNA topoisomerase II activity during anaphase. J Cell Biol. 1992 Jun;117(5):921–934. [PMC free article] [PubMed]
  • Swedlow JR, Sedat JW, Agard DA. Multiple chromosomal populations of topoisomerase II detected in vivo by time-lapse, three-dimensional wide-field microscopy. Cell. 1993 Apr 9;73(1):97–108. [PubMed]
  • Taagepera S, Rao PN, Drake FH, Gorbsky GJ. DNA topoisomerase II alpha is the major chromosome protein recognized by the mitotic phosphoprotein antibody MPM-2. Proc Natl Acad Sci U S A. 1993 Sep 15;90(18):8407–8411. [PMC free article] [PubMed]
  • Uemura T, Ohkura H, Adachi Y, Morino K, Shiozaki K, Yanagida M. DNA topoisomerase II is required for condensation and separation of mitotic chromosomes in S. pombe. Cell. 1987 Sep 11;50(6):917–925. [PubMed]
  • Woessner RD, Mattern MR, Mirabelli CK, Johnson RK, Drake FH. Proliferation- and cell cycle-dependent differences in expression of the 170 kilodalton and 180 kilodalton forms of topoisomerase II in NIH-3T3 cells. Cell Growth Differ. 1991 Apr;2(4):209–214. [PubMed]
  • Wood ER, Earnshaw WC. Mitotic chromatin condensation in vitro using somatic cell extracts and nuclei with variable levels of endogenous topoisomerase II. J Cell Biol. 1990 Dec;111(6 Pt 2):2839–2850. [PMC free article] [PubMed]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press


Save items

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • Cited in Books
    Cited in Books
    NCBI Bookshelf books that cite the current articles.
  • Compound
    PubChem chemical compound records that cite the current articles. These references are taken from those provided on submitted PubChem chemical substance records. Multiple substance records may contribute to the PubChem compound record.
  • MedGen
    Related information in MedGen
  • PubMed
    PubMed citations for these articles
  • Substance
    PubChem chemical substance records that cite the current articles. These references are taken from those provided on submitted PubChem chemical substance records.

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...