Condensin controls mitotic chromosome stiffness and stability without forming a structurally contiguous scaffold

Mingxuan Sun, Ronald Biggs, Jessica Hornick, John F. Marko*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


During cell division, chromosomes must be folded into their compact mitotic form to ensure their segregation. This process is thought to be largely controlled by the action of condensin SMC protein complexes on chromatin fibers. However, how condensins organize metaphase chromosomes is not understood. We have combined micromanipulation of single human mitotic chromosomes, sub-nanonewton force measurement, siRNA interference of condensin subunit expression, and fluorescence microscopy, to analyze the role of condensin in large-scale chromosome organization. Condensin depletion leads to a dramatic (~ 10-fold) reduction in chromosome elastic stiffness relative to the native, non-depleted case. We also find that prolonged metaphase stalling of cells leads to overloading of chromosomes with condensin, with abnormally high chromosome stiffness. These results demonstrate that condensin is a main element controlling the stiffness of mitotic chromosomes. Isolated, slightly stretched chromosomes display a discontinuous condensing staining pattern, suggesting that condensins organize mitotic chromosomes by forming isolated compaction centers that do not form a continuous scaffold.

Original languageEnglish (US)
Pages (from-to)277-295
Number of pages19
JournalChromosome Research
Issue number4
StatePublished - Dec 1 2018


  • cell division
  • chromosome compaction
  • chromosome mechanics
  • chromosome stretching
  • colchicine
  • condensin
  • mechanobiology
  • metaphase chromosome
  • mitosis
  • non-histone proteins
  • structural maintenance of chromosome protein

ASJC Scopus subject areas

  • Genetics


Dive into the research topics of 'Condensin controls mitotic chromosome stiffness and stability without forming a structurally contiguous scaffold'. Together they form a unique fingerprint.

Cite this