相关实验视频
Updated: May 23, 2026

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Assessment of DNA Contamination in RNA Samples Based on Ribosomal DNA
Published on: January 22, 2018
丰富的核糖体RNA基因拷贝维持了基因组的完整性
Satoru Ide1, Takaaki Miyazaki, Hisaji Maki
1National Institute of Genetics, Sokendai, 1111 Yata, Mishima, 411-8540 Japan.
概括
在酵母中失去额外的核糖体RNA基因重复 (rDNA) 会增加对DNA损伤的敏感性. 这是因为活跃的rDNA转录会破坏姐妹染色体的凝聚力,损害DNA修复. 额外的rDNA副本通过促进凝聚力和修复来保护细胞.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 核糖体RNA (rDNA) 基因重复是所有生物体中存在的关键的家庭基因.
- 基因放大系统在染色体内保持大量的,并联重复的rDNA副本,副本数量因物种而异.
- 酵母具有大量未转录的rDNA副本,称为额外的副本.
研究的目的:
- 为了研究酵母中额外的,未转录的rDNA副本的功能意义.
- 确定丢失额外rDNA副本对细胞对DNA损伤敏感性的影响.
- 阐明rDNA在DNA修复和基因组稳定中的作用背后的机制.
主要方法:
- 使用了具有不同数量的rDNA副本的酵母菌株.
- 评估了对由变异原体诱导的DNA损伤的敏感性.
- 研究了rDNA转录活性对DNA损伤敏感性和姐妹染色体凝聚力的作用.
- 分析了在rDNA位点的冷凝素关联和重组修复.
主要成果:
- 丢失额外的rDNA副本使酵母细胞对突变物诱导的DNA损伤敏感.
- 这种敏感性与rDNA转录活性直接相关,这损害了姐妹染色体rDNA位点之间的凝聚力.
- 额外的rDNA拷贝促进了凝聚酶的结合,并增强了姐妹染色体的凝聚力.
- 这些效应共同促进了DNA损伤的高效重组修复.
结论:
- 高度的活跃转录基因,如rDNA,可能对细胞健康有害.
- 基因放大,如rDNA所见,是一种进化的机制,以减轻严重转录的基因的毒性.
- 额外的rDNA副本通过支持DNA修复途径,在维持基因组完整性方面发挥着至关重要的保护作用.
相关概念视频
The Central Dogma
Overview
RNA Stability
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
RNA Stability
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
Genome Copying Errors
DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a long stretch of wrong bases may get added to the daughter strands. If the errors are left unchecked, cells might accumulate several mutations that might endanger their survival. Therefore, the copying errors are checked and repaired at three levels.
Gene Duplication and Divergence
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The Central Dogma
The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins.
RNA is the Missing Link Between DNA and Proteins
In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is...
RNA is the Missing Link Between DNA and Proteins
In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is...

