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

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 ch...

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Detalles Bibliográficos
Autor: Neurohr, Gabriel Erich
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2012
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/81932
Acceso en línea:http://hdl.handle.net/10803/81932
Access Level:acceso abierto
Palabra clave:Saccharomyces
Mitosis
Anaphase
Mitotic
Chromosome condensation
Chromosome segregation
Aurora
Ipl1
576
Descripción
Sumario: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.