A midzone-based ruler adjusts chromosome compaction to analphase spindle length

Neurohr, Gabriel Erich

A midzone-based ruler adjusts chromosome compaction to analphase spindle length

Document Type

Doctoral thesis
Published Version

Author

Neurohr, Gabriel Erich

Director

Mendoza, Manuel

Publication Date

2012-04-13

Pages

138 p.

Citation

Neurohr, G. A midzone-based ruler adjusts chromosome compaction to analphase spindle length. Universitat Pompeu Fabra; 2012. handle: http://hdl.handle.net/10803/81932

This citation was generated automatically.

Doctoral program

Programa de doctorat en Biomedicina

Abstract

Partitioning of chromatids during mitosis requires that chromosome compaction and spindle length scale appropriately with each other. However, it is not clear whether chromosome condensation and spindle elongation are linked. Here we have used chromosome fusions to examine the impact of increased chromosome length during yeast mitosis. We find that yeast cells could cope with a >50% increase in the length of their longest chromosome arm by decreasing the physical length of the mitotic chromosome arm through 1) reducing the number of copies of the repetitive rDNA array and 2) by increasing the level of mitotic condensation. Consistently, cells carrying the fused chromosomes became more sensitive to loss of condensin- and its regulator polo kinase/Cdc5. Length-dependent stimulation of condensation took place during anaphase and depended on aurora/Ipl1 activity, its localization to the spindle midzone, and phosphorylation of histone H3 on Ser10, a known Ipl1 substrate. The anaphase spindle therefore may function as a ruler to adapt the condensation of chromosomes to spindle length. Consistent with this, chromosome condensation levels correlate with the length of anaphase spindles.