纳米孔测序揭示了DNA复制的分隔决定了Trypanosoma brucei中的基因组稳定性和不稳定性
Marija Krasiļņikova1, Catarina A Marques2, Emma M Briggs1,3,4
1University of Glasgow Centre for Parasitology, The Wellcome Centre for Integrative Parasitology, University of Glasgow, School of Infection and Immunity, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, United Kingdom.
Nature communications
|January 17, 2025
概括
在Trypanosoma brucei的研究中.
科学领域:
- 基因组学就是基因组学.
- 分子生物学分子生物学
- 寄生虫学的寄生虫学
背景情况:
- 虫的基因组复杂,具有具有转录核和含有变异表面糖蛋白 (VSG) 基因的静音亚端粒的兆基染色体.
- 亚兆基染色体含有177 bp重复,VSG转录部位位于端粒.
- 之前的研究仅在大基基染色体核和活跃的VSG转录位点中描述了DNA复制动态.
研究的目的:
- 在复杂的Trypanosoma brucei基因组中调查DNA复制动力学.
- 了解子端粒,端粒和177bp重复在基因组稳定性和VSG基因调节中的作用.
- 阐明分隔复制如何促进Trypanosoma brucei的免疫逃避策略.
主要方法:
- 利用纳米孔测序来进行全面的基因组组装.
- 在大基基染色体子端粒和核心中分析了DNA复制启动事件.
- 研究了在活跃的VSG转录部位和177bp重复内复制的起源.
主要成果:
- 大基基染色体子端粒的复制起源比核心少,与增加的不稳定性相关.
- 活跃的VSG转录部位的复制始于端粒,可能驱动VSG重组.
- 177 bp重复作为保存的DNA复制原点,确保亚兆基染色体的稳定性.
结论:
- 在Trypanosoma brucei中分区DNA复制平衡了稳定的基因组传播与局部不稳定.
- 这种复制策略支持寄生虫通过VSG切换逃避宿主免疫系统的能力.
- 了解这些复制动态对于破译寄生虫基因组维护和宿主-寄生虫相互作用至关重要.
相关概念视频
The DNA Replication Fork
35.5K
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...
35.5K
Restarting Stalled Replication Forks
5.7K
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,...
5.7K
The Replisome
32.9K
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...
32.9K
Chromosome Replication
8.7K
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...
8.7K
Replication in Eukaryotes
13.0K
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
13.0K
Lagging Strand Synthesis
48.9K
During replication, the complementary strands in double-stranded DNA are synthesized at different rates. Replication first begins on the leading strand. Replication starts later, occurs more slowly, and proceeds discontinuously on the lagging strand.
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
48.9K


