在玉米发育过程中,塑性DNA和线粒体DNA中的核酸和R环损伤
Diwaker Tripathi1, Delene J Oldenburg1, Arnold J Bendich1
1Department of Biology, University of Washington, Seattle, WA 98195, USA.
Plants (Basel, Switzerland)
|September 9, 2023
概括
在叶子发育过程中,特别是在光线条件下,对玉米细胞器DNA的核核酸损伤增加. 这种损伤,以及减少RNase H防御,有助于器官细胞基因组损失.
科学领域:
- 植物分子生物学 植物分子生物学
- 有机体遗传学 有机体遗传学
- 在DNA损伤和修复过程中.
背景情况:
- 在DNA中,临时的核糖核酸是正常的,但持续的核糖核酸会导致DNA损伤.
- 在玉米塑体和线粒体中有机细胞基因组 (orgDNAs) 在叶子发育过程中的片段.
- 之前的研究发现了玉米orgDNA中的氧化和糖化损伤.
研究的目的:
- 评估在叶子发育期间玉米细胞器DNA中的核糖核酸损伤和防御机制.
- 调查核糖核酸损伤在器官基因组完整性下降中的作用.
- 为了比较光照下生长的植物与黑暗条件下的器官细胞DNA损伤.
主要方法:
- 在整个玉米叶的发育过程中,在有机细胞DNA中量化核酸和R环.
- 在有机体内测量RNase H蛋白水平.
- 在光和黑暗中生长的叶子中比较有机细胞DNA损伤标记物.
主要成果:
- 对玉米细胞器DNA的核糖核酸损伤从叶子底部到叶片增加了2-5倍.
- 与黑暗条件相比,在正常光线下生长的叶子中,这种损伤明显高于黑暗条件.
- 在这种发育过渡期间,RNase H,一种关键的DNA修复蛋白的水平下降.
结论:
- 核酸结合代表了玉米器官基因组中显著的DNA损伤形式.
- 发育变化和暴露于光线会加剧器官细胞DNA损伤.
- 降低RNase H水平,加上氧化和糖化损伤,可能导致有机细胞基因组碎片化.
相关概念视频
Homologous Recombination
50.6K
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...
50.6K
Replication in Eukaryotes
13.9K
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...
13.9K
Export of Mitochondrial and Chloroplast Genes
3.7K
A eukaryotic cell can have up to three different types of genetic systems: nuclear, mitochondrial, and chloroplast. During evolution, organelles have exported many genes to the nucleus; this transfer is still ongoing in some plant species. Approximately 18% of the Arabidopsis thaliana nuclear genome is thought to be derived from the chloroplast’s cyanobacterial ancestor, and around 75% of the yeast genome derived from the mitochondria’s bacterial ancestor. This export has occurred...
3.7K
Non-nuclear Inheritance
21.6K
Most DNA resides in the nucleus of a cell. However, some organelles in the cell cytoplasm—such as chloroplasts and mitochondria—also have their own DNA. These organelles replicate their DNA independently of the nuclear DNA of the cell in which they reside. Non-nuclear inheritance describes the inheritance of genes from structures other than the nucleus.
21.6K
DNA Damage Can Stall the Cell Cycle
2.6K
2.6K
DNA Damage can Stall the Cell Cycle
9.2K
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.2K


