相关实验视频
Updated: May 21, 2026

07:47
Directly Measuring Forces Within Reconstituted Active Microtubule Bundles
Published on: May 10, 2022
移动动体内的变形揭示了活力和被动力生成的不同位置
Sophie Dumont1, E D Salmon, Timothy J Mitchison
1Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA. sophie.dumont@ucsf.edu
概括
动态体使用活力生成在染色体分离过程中进行压缩. 这些发现揭示了基内托科内不同的活跃和被动接口,对于细胞分裂至关重要.
科学领域:
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
- 分子电机分子电机
背景情况:
- 动态基因对线粒分裂期间的染色体分离至关重要.
- 机械性质和动态体内的接口位置仍然不太清楚.
- 据假设,动态器具有活跃的,产生力和被动的,摩擦元素.
研究的目的:
- 为了研究在线粒分裂过程中单个kinetochores内部的机械变形.
- 为了确定动态芯中主动和被动接口的相对位置.
- 为了了解动力基因组机制如何促进染色体分离.
主要方法:
- 利用活细胞成像来观察光标记的kinetochore子单元.
- 在元相振荡过程中测量了基内托科尔子单元之间的平均分离.
- 根据各子单位间距离的变化推断出机械变形.
主要成果:
- 与极点偏离运动相比,极点向上的运动过程中,子单位间的距离较短.
- 在切换到极向运动时,Kinetochore压缩突然发生.
- 拉力增加与子单元间隔离进一步减少相关.
- 确定了一个主动力产生接口和一个被动摩擦接口,位于~20nm极向.
结论:
- 动力管的活性力产生导致它们在向极移动时的压缩.
- 运动器具有不同的主动和被动机械接口.
- 这些接口使得持续的附着和间歇的力量产生为染色体分离.
相关概念视频
Forces Acting on Chromosomes
During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis.
Microtubules and motor proteins exert two types of forces on...
Microtubules and motor proteins exert two types of forces on...
Forces Acting on Chromosomes
During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis.
Microtubules and motor proteins exert two types of forces on...
Microtubules and motor proteins exert two types of forces on...
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...
Anaphase A and B
Microtubules form through the end-to-end polymerization of tubulin heterodimers. Kinetochore microtubules originate from the spindle poles, and their plus-ends connect with the kinetochores on sister-chromatids. Ndc80 protein complexes, present on the kinetochore, form low-affinity links with the plus end of these kinetochore microtubules.
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...

