相关实验视频
Updated: Jun 16, 2026
02:45
Immune Compatible Blood Transfusion and Agglutination
14.0K
在转录活跃DNA中增加了重组率
1Department of Genetics and Development, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Cell
|February 24, 1989
概括
构成性转录的GAL10基因重复显著增加了酵母中的等离子体损失. 然而,这种转录并不能增强转换事件,这表明在重复中转录启动驱动重组.
科学领域:
- 分子生物学分子生物学
- 酵母遗传学 酵母遗传学
- 在DNA重组的过程中,DNA重组.
背景情况:
- 重复的DNA序列之间的重组是基因组稳定的关键过程.
- 已知转录,特别是依赖RNA聚合酶II的转录,会影响DNA重组.
- 在Saccharomyces cerevisiae中的GAL10基因提供了一个模型系统来研究转录-重组相互作用.
研究的目的:
- 研究RNA聚合酶II依赖转录对GAL10基因内直接重复重组的影响.
- 为了确定GAL10基因重复的构成表达是否影响等离子体损失与转化事件.
- 确定转录激活剂 (GAL4) 和抑制剂 (GAL80) 在调节这种重组中的作用.
主要方法:
- 使用的同源酵母菌株具有GAL4或GAL80的零突变.
- 用集成的 GAL10 基因重复来进行重组分析的构造菌株.
- 在构成性和非构成性表达条件下测量了重组率 (等离子体损失和转换).
- 采用北方斑点分析来评估转录启动地点的作用.
主要成果:
- GAL10基因结构的构成表达导致等离子体损失率增加了15倍.
- 导致集成等离子体保留的转化事件没有被重复表达刺激.
- 对促进子突变的分析表明,集成等离子体序列内的转录启动介导了观察到的重组刺激.
结论:
- 依赖RNA聚合酶II的转录显著增强了重组,导致直接重复之间的等离子体损失.
- 对重组的刺激作用取决于重复序列中发生的转录启动.
- 对等离子体损失与转化的影响差异表明,这些重组结果涉及不同的机制.
相关概念视频
Proofreading
Synthesis of new DNA molecules starts when DNA polymerase links nucleotides together in a sequence that is complementary to the template DNA strand. DNA polymerase has a higher affinity for the correct base to ensure fidelity in DNA replication. The DNA polymerase furthermore proofreads during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.Errors during Replication Are Corrected by the DNA Polymerase EnzymeGenomic DNA is synthesized in...
Translesion DNA Polymerases
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
Homologous Recombination
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...
Gene Conversion
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
Proofreading
Synthesis of new DNA molecules is carried out by the enzyme DNA polymerase, which adds nucleotides on the daughter strand complementary to the template DNA strand. DNA polymerase has a higher affinity to add the correct base and ensures fidelity during DNA replication. Furthermore, it exhibits proofreading activity during replication, using an exonuclease domain that cuts off incorrect nucleotides from the nascent DNA strand.
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Errors During Replication are Corrected by the DNA Polymerase Enzyme
Homologous Recombination
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...