関連する実験動画
Updated: May 7, 2026

11:04
A Cell Free Assay to Study Chromatin Decondensation at the End of Mitosis
Published on: December 19, 2015
染色体組み立て in vitro: コンデンサーションにはトポイソメラーゼIIが必要です
Y Adachi1, M Luke, U K Laemmli
1University of Geneva, Department of Biochemistry, Switzerland.
Cell
|January 11, 1991
まとめ
トポイソメラーゼII (トポII) は染色体凝縮に不可欠です. 枯渇したトポIIは,鶏の赤血球核の凝縮を防止し,この重要な細胞プロセスにおけるその構造的役割を強調する.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- 染色体凝縮は,正確な細胞分裂に不可欠です.
- トポイソメラーゼII (topo II) は,DNA管理に関与する酵素である.
- 染色体凝縮におけるトポIIの正確な役割はまだ調査中です.
研究 の 目的:
- 染色体凝縮におけるトポイソメラーゼII (トポII) の役割を調査する.
- トーポIIが構造的にミト性染色体形成に必要かどうかを判断する.
主な方法:
- Xenopusの卵から採取したミトーシス抽出物を利用した.
- トポイソメラーゼII (トポII) を除去するために特異的な免疫低下を用いた.
- 枯渇したエキスを用いてHeLaと鶏の赤血球核における染色体凝縮を評価した.
主要な成果:
- HeLaの核は通常,TOPO II欠乏した抽出物で凝縮され,十分な内生酵素を示しています.
- ニワトリの赤血球核は,TOPO II-depletedエキスで凝縮できませんでした.
- 鶏の赤血球核に浄化されたトポII復元コンデンサを添加する.
- 投与量実験では,トポIIの凝縮における構造的役割が示唆された.
- 枯渇した抽出物は,核構造が欠けている前濃縮染色体をもたらした.
結論:
- トポイソメラーゼII (トポII) は,染色体凝縮において,重要な,潜在的に構造的な役割を果たします.
- この酵素の存在は,低固有レベルの核がミトスの染色体を形成するために不可欠です.
関連する概念動画
Chromosome Structure
A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication.
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
DNA Topoisomerases
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
Types and Mechanism of action
Topoisomerases are divided into two main types. Type I...
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...
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...

