概括
类似病毒40 (SV40) 转变的中国仓鼠肺细胞表现出改变的DNA复制叉动态. 与正常细胞相比,转化细胞在完整的介质中表现出增加的复制分叉,但在缺素贫乏的介质中表现出减少的分叉.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 病毒学 病毒学
背景情况:
- 类似病毒40 (SV40) 是一种DNA瘤病毒,可以转化细胞.
- SV40的细胞转化会影响各种细胞过程,包括DNA复制.
- 了解DNA复制叉动力学对于理解细胞增殖和癌症生物学至关重要.
研究的目的:
- 为了研究SV40转换对中国仓鼠肺细胞中DNA复制叉密度的影响.
- 为了在不同的营养条件下比较野生类型和TSA突变SV40转化细胞中的复制叉行为.
主要方法:
- 用3H-提米丁对中国仓鼠肺细胞进行脉冲标记.
- 个别DNA纤维复制叉的无线图可视化.
- 在完整的和isoleucine-depleted介质中培养细胞.
主要成果:
- 与非转化细胞相比,野生型SV40转化细胞在完整介质中显示出每单位DNA长度的复制分叉密度较高.
- 在缺氨酸贫介质中,SV40转化细胞的复制分叉比继续复制的少数非转化细胞少.
- 由SV40的tsA突变转换的细胞在复制叉密度上表现出SV40依赖的变化,在限制性温度下表现得像非转换细胞一样.
结论:
- SV40转换以对营养敏感的方式改变了DNA复制叉的动态.
- 在SV40中tsA突变影响了与DNA复制相关的转变表型,表明病毒基因产品的重要性.
- 这些发现突出了病毒转变,营养可用性和DNA复制控制之间的复杂相互作用.
相关概念视频
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...
Chromosome Replication
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 of...
The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
S-Cdk Initiates DNA Replication
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
S-Cdk Initiates DNA Replication
The cell cycle is a series of events leading to DNA duplication followed by the division of cell content to form two daughter cells. The cell cycle progresses in four stages—the cell increases in size (gap 1 or G1-phase), duplicates its DNA (synthesis or S-phase), prepares to divide (gap 2 or G2-phase), and divides (mitosis or M-phase).
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.


