在Saccharomyces cerevisiae中亚相前的姐妹微染色体DNA的结构
1Department of Genetics, University of Washington, Seattle 98195.
概括
DNA拓不保持姐妹染色体在一起. 研究表明,姐妹微染色体在亚相前没有相互锁定,但仍能正确分离,这挑战了以前的假设.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 遗传学 是一个遗传学.
背景情况:
- 姐妹染色体凝聚力对于细胞分裂期间精确的染色体分离至关重要.
- 在维护这种凝聚力方面,DNA拓学的作用,特别是相互锁定,已经得到了讨论.
- 了解这些机制对于理解细胞循环调节和预防质积分症至关重要.
研究的目的:
- 为了调查在异相前姐妹染色体凝聚力的拓交错的必要性.
- 为了确定DNA拓是否是保持姐妹染色体在一起的主要力量.
- 为了分析酵母细胞周期突变体中的姐妹染色体分离.
主要方法:
- 在Saccharomyces cerevisiae细胞周期 (cdc) 突变体中分析小染色体结构.
- 通过显微镜检查受阻细胞中的姐妹微染色体相互锁定状态.
- 在从细胞循环中释放出来时,对微染色体进行化分析.
主要成果:
- 研究人员发现,姐妹微染色体分子在S期后和前期被捕的细胞中,在很大程度上没有相互锁定.
- 在从细胞周期停止释放后,这些姐妹微染色体准确地分离.
- 拓互锁的程度与适当的隔离没有相关性.
结论:
- 姐妹DNA分子的拓交错不需要在亚纳相之前进行适当的分离.
- DNA拓不太可能是负责将姐妹染色体结合在一起的主要机制.
- 替代机制必须负责姐妹染色体凝聚力,直到阿纳相.
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...


