基因组进化的异质选择景观在 prokaryotes 中
Research square
|December 31, 2025
概括
前生物基因组进化是由精简和多样化的选择所塑造的. 不同的 prokaryote 群体,如细菌和古生物,经历不同的进化压力,影响它们的基因组大小和复杂性.
科学领域:
- 微生物进化 微生物进化
- 基因组学就是基因组学.
- 人口遗传学 人口遗传学
背景情况:
- 前生物基因组进化受到基因组简化,删除偏差和功能多样化的选择的影响.
- 选择强度 (dN/dS) 和多样化之间的正相关性表明这是一个主要的进化驱动因素.
- 之前的研究表明总体趋势,但 prokaryotes 之间的异质性尚未完全理解.
研究的目的:
- 研究 prokaryotes 中基因组大小和选择压力之间的关系.
- 分析基因组范围内的选择,使用基因组基的dN/dS方法.
- 为了区分谱系特异性和基因特异性选择组件.
主要方法:
- 对密切相关的 prokaryotic 基因组的扩展集合的分析.
- 基因组范围的选择评估使用非同义和同义核酸替代 (dN/dS) 的比率.
- 应用一种精确的,基于基因的方法来测量dN/dS和分解值.
主要成果:
- 在原核生物之间基因组大小选择强度关系中存在明显的异质性.
- 大多数细菌显示出正相关性,与选择多样化相一致.
- 所有分析的考古遗传系都表现出强烈的负相关性,表明基因组精简.
结论:
- 精选模式在原核生物多样性中显著不同,不遵循单一的普遍模式.
- 基因组简化和功能多样性的选择是关键的进化因素.
- 这些因素的相对贡献取决于特定血统的种群遗传和生态.
相关概念视频
Gene Evolution - Fast or Slow?
7.9K
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
7.9K
Gene Evolution - Fast or Slow?
3.4K
3.4K
Genome Size and the Evolution of New Genes
8.9K
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
8.9K
Genome Size and the Evolution of New Genes
3.2K
3.2K
Genomic DNA in Prokaryotes
48.1K
The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the nucleoid. The chromosome is tightly wound, or supercoiled, for efficient storage. Prokaryotes also contain other circular pieces of DNA called plasmids. These plasmids are smaller than the chromosome and often carry genes that confer adaptive functions, such as antibiotic resistance.
Genomic Diversity in Bacteria
Although bacterial genomes are much...
Genomic Diversity in Bacteria
Although bacterial genomes are much...
48.1K
The Evidence for Evolution
47.5K
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.
47.5K


