A Balance between Nuclear and Cytoplasmic Volumes Controls Spindle Length

PLoS One. 2016 Feb 17;11(2):e0149535. doi: 10.1371/journal.pone.0149535. eCollection 2016.

Abstract

Proper assembly of the spindle apparatus is crucially important for faithful chromosome segregation during anaphase. Thanks to the effort over the last decades, we have very detailed information about many events leading to spindle assembly and chromosome segregation, however we still do not understand certain aspects, including, for example, spindle length control. When tight regulation of spindle size is lost, chromosome segregation errors emerge. Currently, there are several hypotheses trying to explain the molecular mechanism of spindle length control. The number of kinetochores, activity of molecular rulers, intracellular gradients, cell size, limiting spindle components, and the balance of the spindle forces seem to contribute to spindle size regulation, however some of these mechanisms are likely specific to a particular cell type. In search for a general regulatory mechanism, in our study we focused on the role of cell size and nuclear to cytoplasmic ratio in this process. To this end, we used relatively large cells isolated from 2-cell mouse embryos. Our results showed that the spindle size upper limit is not reached in these cells and suggest that accurate control of spindle length requires balanced ratio between nuclear and cytoplasmic volumes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Cycle Proteins
  • Cell Nucleus Size*
  • Cell Size
  • Cytoplasm / metabolism*
  • Metaphase
  • Mice
  • Mice, Inbred ICR
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • Parthenogenesis
  • Spindle Apparatus / metabolism*

Substances

  • Cell Cycle Proteins
  • Microtubule-Associated Proteins
  • Nuclear Proteins
  • TPX2 protein, mouse

Grants and funding

This work was supported by Czech science foundation project P502/12/2201 and by Ministry of Education, Youth and Sports (MEYS) projects ED1.1.00/ 02.0068 – Central European Institute of Technology (CEITEC) and LH 13072 – Kontakt II.