複製体と染色体構造のミトスの改造
Jean-Marc Lemaitre1, Etienne Danis, Philippe Pasero
1Genome Dynamics and Development, Institute of Human Genetics, CNRS, 141 rue de la Cardonille, 34396 Montpellier, France.
Cell
|December 6, 2005
まとめ
クセノプスの卵におけるミトスの改造は,胚の発達のために微分した核を適応させるのに不可欠である. このプロセスは,適切なDNA複製を保証し,核クローニングの成功を向上させます.
科学分野:
- 発達生物学 発達生物学とは
- 細胞生物学 細胞生物学
- 生殖生物学 生殖生物学
背景:
- 移植された核が正常な胚の発達をサポートできないため,核移転クローニングはしばしば失敗します.
- 分化した細胞核は,卵の環境の中で複製する際の課題に直面します.
研究 の 目的:
- クセノプスの卵における成功する胚発達のために,微分した核の適応におけるミトーシスの役割を調査する.
- クローニング中の核再プログラミングの基礎となる分子メカニズムを理解するために.
主な方法:
- 差別化された赤血球核の核移植をクセノプスの卵にします.
- DNA複製効率とクロマチンの構造の分析.
- トポイソメラーゼIIと複製開始因子の役割を調査する.
主要な成果:
- 差別化された赤血球核は非効率的に複製するが,卵内の単一のミトーシス後に急速な複製を達成する.
- ミトスの改造は,トポイソメラーゼIIに依存するクロマチンの縮小と複製因子の増殖を伴う.
- この改造は,初期の胚のDNA複製に不可欠な短い起源間隔を確立します.
結論:
- ミトスの条件付けは,胚のDNA複製のためのドナー細胞におけるクロマチンの構造をリセットするために重要である.
- このプロセスは,クローン胚におけるDNA複製を開始するための重要な規制ステップです.
- 核クローニングの効率を改善するために,ミトスの改造は不可欠です.
関連する概念動画
02:31Chromosome Replication
8.9K
Before a cell can divide, it must accurately replicate all of its chromosomes, including the DNA and its associated histone and non-histone proteins. This process begins at numerous origins of replication during the S phase of the cell cycle in each of a cell’s chromosomes simultaneously. Certain nucleotides can act as origins of replication, but these sequences are not well defined - especially in complex, multi-cellular, eukaryotic species. The length of DNA that spans an origin...
8.9K
02:54Nucleosome Remodeling
8.7K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
8.7K
03:01The Replisome
31.2K
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
31.2K
02:31Homologous Recombination
58.8K
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
58.8K
02:53Conservative Site-specific Recombination and Phase Variation
5.7K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
5.7K
02:05Duplication of Chromatin Structure
6.1K
The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
6.1K