Limits...
Individual pericentromeres display coordinated motion and stretching in the yeast spindle.

Stephens AD, Snider CE, Haase J, Haggerty RA, Vasquez PA, Forest MG, Bloom K - J. Cell Biol. (2013)

Bottom Line: By labeling several chromosomes, we find that pericentromeres display coordinated motion and stretching in metaphase.The pericentromeres of different chromosomes exhibit physical linkage dependent on centromere function and structural maintenance of chromosomes complexes.Coordinated motion is dependent on condensin and the kinesin motor Cin8, whereas coordinated stretching is dependent on pericentric cohesin and Cin8.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, 2 Department of Mathematics, and 3 Department Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.

ABSTRACT
The mitotic segregation apparatus composed of microtubules and chromatin functions to faithfully partition a duplicated genome into two daughter cells. Microtubules exert extensional pulling force on sister chromatids toward opposite poles, whereas pericentric chromatin resists with contractile springlike properties. Tension generated from these opposing forces silences the spindle checkpoint to ensure accurate chromosome segregation. It is unknown how the cell senses tension across multiple microtubule attachment sites, considering the stochastic dynamics of microtubule growth and shortening. In budding yeast, there is one microtubule attachment site per chromosome. By labeling several chromosomes, we find that pericentromeres display coordinated motion and stretching in metaphase. The pericentromeres of different chromosomes exhibit physical linkage dependent on centromere function and structural maintenance of chromosomes complexes. Coordinated motion is dependent on condensin and the kinesin motor Cin8, whereas coordinated stretching is dependent on pericentric cohesin and Cin8. Linking of pericentric chromatin through cohesin, condensin, and kinetochore microtubules functions to coordinate dynamics across multiple attachment sites.

Show MeSH

Related in: MedlinePlus

Pericentromeres of different chromosomes display correlated movement in metaphase dependent on condensin and Cin8. (A and B) Compact (foci) pericentromere movements were tracked relative to their respective spindle pole body (Spc29-RFP) in trans (CEN11 and CEN15; A)- and cis (B)-labeled strains (4.5 and 9.4 kb from CEN11). (C) Sister arrays were tracked relative to the midspindle. Each graph depicts a single representative time lapse from n = 50–100. (D) Cross-correlation analysis of trans-, cis-, and sister pericentromere movement in G1 and metaphase (M). t test values are listed above the bars. (E) Time courses were analyzed for which pericentromere label was closest to its respective pole at each time point (trans, n = 742 from 44 experiments; cis, n = 176 from 12 experiments). An equal probability to be closest to the pole suggests that pericentromere (cis) DNA can “flop” over itself (shown on the right). (F–H) Trans (F)-, cis (G)-, and sister (H) pericentromere–correlated motion for chromatin (GalH3, mcm21Δ, and brn1-9) and microtubule motor mutants (cin8Δ and kip1Δ). Asterisks denote significantly different cross-correlation from WT (t test, P < 0.05). Values are listed in Table 1 and Table S1. Error bars represent standard deviations.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3824013&req=5

fig1: Pericentromeres of different chromosomes display correlated movement in metaphase dependent on condensin and Cin8. (A and B) Compact (foci) pericentromere movements were tracked relative to their respective spindle pole body (Spc29-RFP) in trans (CEN11 and CEN15; A)- and cis (B)-labeled strains (4.5 and 9.4 kb from CEN11). (C) Sister arrays were tracked relative to the midspindle. Each graph depicts a single representative time lapse from n = 50–100. (D) Cross-correlation analysis of trans-, cis-, and sister pericentromere movement in G1 and metaphase (M). t test values are listed above the bars. (E) Time courses were analyzed for which pericentromere label was closest to its respective pole at each time point (trans, n = 742 from 44 experiments; cis, n = 176 from 12 experiments). An equal probability to be closest to the pole suggests that pericentromere (cis) DNA can “flop” over itself (shown on the right). (F–H) Trans (F)-, cis (G)-, and sister (H) pericentromere–correlated motion for chromatin (GalH3, mcm21Δ, and brn1-9) and microtubule motor mutants (cin8Δ and kip1Δ). Asterisks denote significantly different cross-correlation from WT (t test, P < 0.05). Values are listed in Table 1 and Table S1. Error bars represent standard deviations.

Mentions: To determine whether pericentromeres of different chromosomes move coordinately during metaphase, we imaged LacO and tetracycline operon (TetO) arrays linked to CEN15 and CEN11, respectively. Movement of each pericentromere was measured relative to its pole (Fig. 1 A, red). The movements of pericentromeres in the same half-spindle were compared using cross-correlation analysis. Correlation increased from G1 to metaphase (G1: 0.15 ± 0.33, n = 80; metaphase: 0.33 ± 0.34, n = 88; P < 0.001; Fig. 1 D). Similar results were found with a different set of labeled chromosomes (CEN3 and CEN11; Fig. S1 A). Thus, pericentromeres show metaphase-dependent correlated movement.


Individual pericentromeres display coordinated motion and stretching in the yeast spindle.

Stephens AD, Snider CE, Haase J, Haggerty RA, Vasquez PA, Forest MG, Bloom K - J. Cell Biol. (2013)

Pericentromeres of different chromosomes display correlated movement in metaphase dependent on condensin and Cin8. (A and B) Compact (foci) pericentromere movements were tracked relative to their respective spindle pole body (Spc29-RFP) in trans (CEN11 and CEN15; A)- and cis (B)-labeled strains (4.5 and 9.4 kb from CEN11). (C) Sister arrays were tracked relative to the midspindle. Each graph depicts a single representative time lapse from n = 50–100. (D) Cross-correlation analysis of trans-, cis-, and sister pericentromere movement in G1 and metaphase (M). t test values are listed above the bars. (E) Time courses were analyzed for which pericentromere label was closest to its respective pole at each time point (trans, n = 742 from 44 experiments; cis, n = 176 from 12 experiments). An equal probability to be closest to the pole suggests that pericentromere (cis) DNA can “flop” over itself (shown on the right). (F–H) Trans (F)-, cis (G)-, and sister (H) pericentromere–correlated motion for chromatin (GalH3, mcm21Δ, and brn1-9) and microtubule motor mutants (cin8Δ and kip1Δ). Asterisks denote significantly different cross-correlation from WT (t test, P < 0.05). Values are listed in Table 1 and Table S1. Error bars represent standard deviations.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3824013&req=5

fig1: Pericentromeres of different chromosomes display correlated movement in metaphase dependent on condensin and Cin8. (A and B) Compact (foci) pericentromere movements were tracked relative to their respective spindle pole body (Spc29-RFP) in trans (CEN11 and CEN15; A)- and cis (B)-labeled strains (4.5 and 9.4 kb from CEN11). (C) Sister arrays were tracked relative to the midspindle. Each graph depicts a single representative time lapse from n = 50–100. (D) Cross-correlation analysis of trans-, cis-, and sister pericentromere movement in G1 and metaphase (M). t test values are listed above the bars. (E) Time courses were analyzed for which pericentromere label was closest to its respective pole at each time point (trans, n = 742 from 44 experiments; cis, n = 176 from 12 experiments). An equal probability to be closest to the pole suggests that pericentromere (cis) DNA can “flop” over itself (shown on the right). (F–H) Trans (F)-, cis (G)-, and sister (H) pericentromere–correlated motion for chromatin (GalH3, mcm21Δ, and brn1-9) and microtubule motor mutants (cin8Δ and kip1Δ). Asterisks denote significantly different cross-correlation from WT (t test, P < 0.05). Values are listed in Table 1 and Table S1. Error bars represent standard deviations.
Mentions: To determine whether pericentromeres of different chromosomes move coordinately during metaphase, we imaged LacO and tetracycline operon (TetO) arrays linked to CEN15 and CEN11, respectively. Movement of each pericentromere was measured relative to its pole (Fig. 1 A, red). The movements of pericentromeres in the same half-spindle were compared using cross-correlation analysis. Correlation increased from G1 to metaphase (G1: 0.15 ± 0.33, n = 80; metaphase: 0.33 ± 0.34, n = 88; P < 0.001; Fig. 1 D). Similar results were found with a different set of labeled chromosomes (CEN3 and CEN11; Fig. S1 A). Thus, pericentromeres show metaphase-dependent correlated movement.

Bottom Line: By labeling several chromosomes, we find that pericentromeres display coordinated motion and stretching in metaphase.The pericentromeres of different chromosomes exhibit physical linkage dependent on centromere function and structural maintenance of chromosomes complexes.Coordinated motion is dependent on condensin and the kinesin motor Cin8, whereas coordinated stretching is dependent on pericentric cohesin and Cin8.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, 2 Department of Mathematics, and 3 Department Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.

ABSTRACT
The mitotic segregation apparatus composed of microtubules and chromatin functions to faithfully partition a duplicated genome into two daughter cells. Microtubules exert extensional pulling force on sister chromatids toward opposite poles, whereas pericentric chromatin resists with contractile springlike properties. Tension generated from these opposing forces silences the spindle checkpoint to ensure accurate chromosome segregation. It is unknown how the cell senses tension across multiple microtubule attachment sites, considering the stochastic dynamics of microtubule growth and shortening. In budding yeast, there is one microtubule attachment site per chromosome. By labeling several chromosomes, we find that pericentromeres display coordinated motion and stretching in metaphase. The pericentromeres of different chromosomes exhibit physical linkage dependent on centromere function and structural maintenance of chromosomes complexes. Coordinated motion is dependent on condensin and the kinesin motor Cin8, whereas coordinated stretching is dependent on pericentric cohesin and Cin8. Linking of pericentric chromatin through cohesin, condensin, and kinetochore microtubules functions to coordinate dynamics across multiple attachment sites.

Show MeSH
Related in: MedlinePlus