相关实验视频
Updated: Jun 24, 2025

14:23
Recombineering Homologous Recombination Constructs in Drosophila
Published on: July 13, 2013
19.3K
在高度重组的基因中增加的积极选择并不一定反映了重组的进化优势
1Laboratoire de Biométrie et Biologie Evolutive, Université Lyon 1, CNRS, UMR 5558, Villeurbanne, France.
Molecular biology and evolution
|June 3, 2024
概括
介质性再组合是介质性的再组合.
科学领域:
- 进化遗传学的进化遗传学
- 人口遗传学 人口遗传学
- 分子进化是分子进化的过程.
背景情况:
- 人们认为,体重组可以通过分离关联的位置来提高选择效率.
- 经常与重组相关的GC偏差基因转换 (gBGC) 可以通过促进有害的GC等位基因固定来干扰选择.
- 之前的研究假设健身效应 (DFE) 的固定分布,以评估与重组相关的选择有效性.
研究的目的:
- 从基因的进化历史中直接导出DFE,包括突变,选择,漂移和gBGC.
- 为了研究重组,gBGC和自然选择的有效性之间的相互作用.
- 重新评估加速进化特征的驱动因素和gBGC的作用.
主要方法:
- 经验性健身景观被用来导出DFE.
- 分析由突变,选择,漂移和gBGC塑造的进化历史.
- 评估gBGC强度对有益突变固定和选择特征的影响.
主要成果:
- 具有高gBGC的基因体验减少了适应性,创造了更多有利突变的机会.
- 全基因组gBGC的轻微减少有助于有益突变的固定,特别是在高重组区.
- 高度重组基因中增加的阳性选择是由改变的DFE驱动的,不一定是更有效的选择.
- 重组热点损失可以增加dN/dS与AT偏差替代,挑战GC偏差校正检测加速进化.
- gBGC通过改变DFE来影响非同义的GC-保守替代模式.
结论:
- 在高度重组的区域中,选择的有效性是由gBGC对DFE的影响调节的,而不仅仅是链接消散.
- 归因于重组的加速进化的特征可能会被gBGC混,需要仔细考虑替代偏差.
- gBGC通过重塑DFE,显著影响进化轨迹,包括非同义替代.
相关概念视频
Exon Recombination
3.6K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
3.6K
Gene Conversion
9.7K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
9.7K
Conservative Site-specific Recombination and Phase Variation
6.0K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
6.0K
Crossing Over
4.3K
Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I,...
4.3K
Homologous Recombination
50.4K
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...
50.4K
Viral Recombination
23.4K
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.
23.4K

