相关实验视频
Updated: May 2, 2026

11:58
In-Nucleus Hi-C in Drosophila Cells
Published on: September 15, 2021
4.1K
概括
拓二醇酶I定位到多索菲拉细胞中转录的DNA区域. 这种酶在压力期间被招募到热冲击基因中,这表明它促进了转录所需的DNA变化.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 拓聚酶I在细胞过程中对管理DNA拓学至关重要.
- 在体内了解Topoisomerase I的精确基因组定位对于阐明其调节作用至关重要.
研究的目的:
- 为了确定Topoisomerase I在Drosophila细胞中特定DNA序列上的高分辨率体内分布.
- 研究Topoisomerase I结合和转录活性之间的关系,特别是在应激反应期间.
主要方法:
- 在完好无损的Drosophila细胞中利用光交联技术捕获Topoisomerase I-DNA相互作用.
- 通过紫外线照射生成的拓胺酶I-DNA添加物.
- 使用免疫沉与抗托皮索马酶I抗体进行净化添加物.
- 通过使用特定的DNA探针进行斑点混合,分析交联的DNA序列.
主要成果:
- 发现拓二醇酶I集中在转录的DNA区域上,与侧面的非转录序列不同.
- 在热冲击反应期间观察到拓聚合酶I对热冲击基因的招募,类似于RNA聚合酶II.
- 通过hsp70和拷贝基因的差异交叉连接比率表明,拓聚合酶I和RNA聚合酶II与转录区域的独立相互作用.
结论:
- 拓聚酶I优先结合到积极转录的DNA序列.
- 拓糖酶I在基因的转录调节中发挥作用,包括应激诱导基因.
- 这些发现支持了一个模型,其中Topoisomerase I促进了转录所需的DNA的拓变化.
相关概念视频
Position-effect Variegation
5.6K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
5.6K
Polytene Chromosomes
9.3K
Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also...
9.3K
DNA Topoisomerases
32.3K
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. ...
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
32.3K
DNA-only Transposons
16.0K
DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure.
The donor site from where the transposon is excised is either degraded or...
The donor site from where the transposon is excised is either degraded or...
16.0K
Eukaryotic Transcription Inhibitors
9.1K
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
Eukaryotic transcription inhibitors usually contain two distinct domains, a...
9.1K
Transcription Attenuation in Prokaryotes
14.6K
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
14.6K

