在芽酵母的线粒分裂过程中,染色体的过渡性姐妹染色体分离和弹性变形
1Massachusetts Institute of Technology, Department of Biology, Cambridge 02139, USA.
Cell
|July 13, 2000
概括
精确的染色体分离在线粒分裂的依赖于正确的kinetochore-microtubule附件. 酵母染色体显示了短暂的姐妹分离,揭示了中心性染色质的中心性染色体.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 精确的染色体分离对于细胞分裂至关重要.
- 姐妹染色体凝聚力必须在阿纳相之前被溶解.
- 运动 - 微管附着物在染色体对齐中起着关键作用.
研究的目的:
- 调查基因 - 微管附着物在染色体分离中的作用.
- 分析S. cerevisiae中GFP标记的染色体的运动.
- 了解在线粒分裂过程中短暂的姐妹分离的机制.
主要方法:
- 在S. cerevisiae中对GFP标记染色体的活细胞成像.
- 染色体和基因组蛋白运动的分析.
- 测量中间体染色体分离和持续时间.
主要成果:
- 动脉 - 微管附着物产生紧张,暂时将姐妹染色体分开.
- 过渡性分离持续2-10分钟,并且发生在凝聚蛋白质溶解之前.
- 姐妹染色体在分离过程中独立移动,然后重新建立联系.
结论:
- 在酵母中,短暂的姐妹分离是由kinetochore-microtubule张力驱动的.
- 这种现象解释了kinetochore蛋白质的双叶定位.
- 酵母细胞中位色素可以充当张力计,类似于动物细胞.
相关概念视频
Cohesins
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of homologous...
Condensins
Condensins are large protein complexes that use ATP to fuel the assembly of chromosomes during mitosis. They transform the tangled, shapeless mass of post-interphase DNA into individualized chromosomes by compacting, organizing, and segregating chromosomal DNA.
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
Attachment of Sister Chromatids
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall of a...
Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
Attachment of Sister Chromatids
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall of a...
Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...


