相关实验视频
Updated: Sep 14, 2025
10:41
Identifying Amino Acid Overproducers Using Rare-Codon-Rich Markers
Published on: June 24, 2019
8.5K
据推测,在Actinidia多倍化事件中,tRNA选择效应可能会影响codon使用偏差
Yi Zhou1,2, Zhilu Sheng1,2, Dongbin Li3
1State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
BMC genomics
|July 23, 2025
概括
多倍体化不会影响Actinidia中的密码体使用偏差;自然选择和tRNA可用性是主要的驱动因素. 这项研究分析了Actinidia和相关物种的子使用模式,以了解塑造基因表达的进化力量.
科学领域:
- 基因组学就是基因组学.
- 分子进化分子进化
- 生物信息学是一种生物信息学.
背景情况:
- 多化是关键的物种化机制,但其对同义频率和使用偏差 (CUB) 的影响尚未完全理解.
- 对于理解基因组进化来说,研究Actinidia多化事件中的CUB模式至关重要.
研究的目的:
- 为了确定多化事件是否会改变Actinidia物种中的密码使用偏差 (CUB).
- 为了确定影响Actinidia和相关植物物种CUB变化的主要因素.
主要方法:
- 在七种Actinidia物种 (两个多倍体,五个双倍体) 和五种相关物种 (一个多倍体,四个双倍体) 中对CUB进行比较基因组分析.
- 分析GC含量,有效编码数 (ENC),GC3s,相对同义编码使用率 (RSCU) 和tRNA适应指数 (tAI).
主要成果:
- 所有分析的基因组都显示出对富含A/T核酸和密码子的偏好.
- 自然选择,而不是多化,被确定为CUB变异的主要驱动因素,由ENC和GC3s分布表明.
- 与非Actinidia物种相比,Actinidia物种在ENC和tAI之间表现出更强的相关性,这表明tRNA可用性在塑造CUB方面发挥着更重要的作用.
结论:
- 在Actinidia中,Codon使用偏差是由自然选择塑造的,并受到tRNA可用性的影响,而不是多化事件.
- 这些发现提供了对控制多体植物基因表达和基因组进化的进化力量的见解.
相关概念视频
02:26tRNA Activation
20.0K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
20.0K
02:36Transfer RNA Synthesis
12.3K
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
12.3K
02:07Improving Translational Accuracy
11.9K
Base complementarity between the three base pairs of mRNA codon and the tRNA anticodon is not a failsafe mechanism. Inaccuracies can range from a single mismatch to no correct base pairing at all. The free energy difference between the correct and nearly correct base pairs can be as small as 3 kcal/ mol. With complementarity being the only proofreading step, the estimated error frequency would be one wrong amino acid in every 100 amino acids incorporated. However, error frequencies observed in...
11.9K
02:13Overview of Transposition and Recombination
16.1K
Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out...
16.1K
03:06From DNA to Protein
19.1K
The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of mRNAs, which in turn specify the sequence of amino acids making up all proteins. The decoding of one molecule to another is performed by specific proteins and RNAs. Because the information stored in DNA is so central to cellular function, it makes intuitive sense that the cell would make mRNA copies of this information for protein synthesis...
19.1K
02:23RNA Editing
9.2K
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
9.2K