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Length-dependent anisotropic scaling of spindle shape.

Young S, Besson S, Welburn JP - Biol Open (2014)

Bottom Line: We demonstrate that spindle shape scaling is independent of the nature of the molecules that regulate dynamic microtubule properties, but is dependent on the steady-state metaphase spindle length.The shape of the spindle scales anisotropically with increasing length.Our results suggest that intrinsic mechanisms control the shape of the spindle to ensure the efficient capture and alignment of chromosomes independently of spindle length.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK.

No MeSH data available.


Related in: MedlinePlus

Clasp1 and Clasp2 depletion triggers a biphasic spindle assembly phase and changes in spindle geometry.(A) Schematic diagram showing the localization of ch-TOG, Clasp1 and Clasp2 in a mitotic cell. The cell boundaries are represented in black, K-fibers, spindle microtubules and astral microtubules are represented in dark, medium and light green respectively. (B) Time-lapse imaging of U2OS cells expressing mCherry-tubulin after a STLC washout. Cells were treated with Control, Clasp1, Clasp2 and Clasp1/Clasp2 siRNA for 48 hours before imaging. The yellow asterisks represent the marking of the spindle pole used in the measurements of spindle length, using OMERO. (C,D,F) Graphs representing the average spindle length, width and aspect ratio and the corresponding SD, defined in panel E during elongation for each condition described in panel B. Scale bar: 10 µm.
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f01: Clasp1 and Clasp2 depletion triggers a biphasic spindle assembly phase and changes in spindle geometry.(A) Schematic diagram showing the localization of ch-TOG, Clasp1 and Clasp2 in a mitotic cell. The cell boundaries are represented in black, K-fibers, spindle microtubules and astral microtubules are represented in dark, medium and light green respectively. (B) Time-lapse imaging of U2OS cells expressing mCherry-tubulin after a STLC washout. Cells were treated with Control, Clasp1, Clasp2 and Clasp1/Clasp2 siRNA for 48 hours before imaging. The yellow asterisks represent the marking of the spindle pole used in the measurements of spindle length, using OMERO. (C,D,F) Graphs representing the average spindle length, width and aspect ratio and the corresponding SD, defined in panel E during elongation for each condition described in panel B. Scale bar: 10 µm.

Mentions: Ch-TOG, Clasp1, and Clasp2 influence microtubule length by controlling microtubule plus-end dynamics (supplementary material Fig. S1A,B) (Al-Bassam et al., 2012; Brouhard et al., 2008; Komarova et al., 2009; Maffini et al., 2009; Maiato et al., 2003; Mimori-Kiyosue et al., 2005). In addition to their localization to microtubule plus ends, ch-TOG and the Clasp proteins localize to subcellular structures including the kinetochore and the centrosome to direct correct chromosome segregation (Fig. 1A) (Dionne et al., 2000; Maiato et al., 2003; Pereira et al., 2006). To determine whether these microtubule regulators control spindle geometry, we next examined bipolar spindle elongation in absence of ch-TOG, Clasp1, or Clasp2. Upon STLC washout, ch-TOG depleted cells failed to separate their centrosomes, despite the presence of short microtubules (data not shown).


Length-dependent anisotropic scaling of spindle shape.

Young S, Besson S, Welburn JP - Biol Open (2014)

Clasp1 and Clasp2 depletion triggers a biphasic spindle assembly phase and changes in spindle geometry.(A) Schematic diagram showing the localization of ch-TOG, Clasp1 and Clasp2 in a mitotic cell. The cell boundaries are represented in black, K-fibers, spindle microtubules and astral microtubules are represented in dark, medium and light green respectively. (B) Time-lapse imaging of U2OS cells expressing mCherry-tubulin after a STLC washout. Cells were treated with Control, Clasp1, Clasp2 and Clasp1/Clasp2 siRNA for 48 hours before imaging. The yellow asterisks represent the marking of the spindle pole used in the measurements of spindle length, using OMERO. (C,D,F) Graphs representing the average spindle length, width and aspect ratio and the corresponding SD, defined in panel E during elongation for each condition described in panel B. Scale bar: 10 µm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4265759&req=5

f01: Clasp1 and Clasp2 depletion triggers a biphasic spindle assembly phase and changes in spindle geometry.(A) Schematic diagram showing the localization of ch-TOG, Clasp1 and Clasp2 in a mitotic cell. The cell boundaries are represented in black, K-fibers, spindle microtubules and astral microtubules are represented in dark, medium and light green respectively. (B) Time-lapse imaging of U2OS cells expressing mCherry-tubulin after a STLC washout. Cells were treated with Control, Clasp1, Clasp2 and Clasp1/Clasp2 siRNA for 48 hours before imaging. The yellow asterisks represent the marking of the spindle pole used in the measurements of spindle length, using OMERO. (C,D,F) Graphs representing the average spindle length, width and aspect ratio and the corresponding SD, defined in panel E during elongation for each condition described in panel B. Scale bar: 10 µm.
Mentions: Ch-TOG, Clasp1, and Clasp2 influence microtubule length by controlling microtubule plus-end dynamics (supplementary material Fig. S1A,B) (Al-Bassam et al., 2012; Brouhard et al., 2008; Komarova et al., 2009; Maffini et al., 2009; Maiato et al., 2003; Mimori-Kiyosue et al., 2005). In addition to their localization to microtubule plus ends, ch-TOG and the Clasp proteins localize to subcellular structures including the kinetochore and the centrosome to direct correct chromosome segregation (Fig. 1A) (Dionne et al., 2000; Maiato et al., 2003; Pereira et al., 2006). To determine whether these microtubule regulators control spindle geometry, we next examined bipolar spindle elongation in absence of ch-TOG, Clasp1, or Clasp2. Upon STLC washout, ch-TOG depleted cells failed to separate their centrosomes, despite the presence of short microtubules (data not shown).

Bottom Line: We demonstrate that spindle shape scaling is independent of the nature of the molecules that regulate dynamic microtubule properties, but is dependent on the steady-state metaphase spindle length.The shape of the spindle scales anisotropically with increasing length.Our results suggest that intrinsic mechanisms control the shape of the spindle to ensure the efficient capture and alignment of chromosomes independently of spindle length.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK.

No MeSH data available.


Related in: MedlinePlus