相关实验视频
Updated: Jun 1, 2025

07:01
Manipulation of Gene Function in Mexican Cavefish
Published on: April 22, 2019
9.0K
洞穴鱼中早产终结子的种群基因组学,具有大量的特征损失
Emma Y Roback1, Estephany Ferrufino2, Rachel L Moran1,3
1Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, MN 55108, USA.
Molecular biology and evolution
|January 20, 2025
概括
功能丧失的等位基因,特别是过早终结子 (PTCs),在洞穴鱼中比较常见. 遗传漂移,而不是选择,解释了这种增加,一些PTC可能会推动洞穴居民群体的适应.
科学领域:
- 进化遗传学的进化遗传学
- 基因组学就是基因组学.
- 分子生物学分子生物学
背景情况:
- 功能丧失等位基因,特别是过早终结子 (PTCs),是进化适应的关键驱动因素.
- 洞穴适应的生物往往会显著丧失祖先的特征,这表明功能丧失突变的作用.
- 墨西哥提供了一个模型系统来研究地下环境中的遗传适应.
研究的目的:
- 调查墨西哥四种群中PTCs的进化历史和适应潜力.
- 确定遗传漂移与积极选择在洞穴种群中PTCs积累中的作用.
- 确定可能有助于洞穴特定适应的特定PTC.
主要方法:
- 141名墨西哥四个体 (洞穴和地表种群) 的全基因组测序.
- 分析PTC频率和整个基因组的分布,与进化约束相关.
- 使用SLiM进行种群遗传学模拟,以在不同的人口情景下建模PTC演变.
- 使用CRISPR-Cas9基因编辑来评估特定PTC (例如pde6c) 的表型效应.
主要成果:
- 与地表种群相比,洞穴种群的PTC频率明显高.
- PTCs在具有放松进化约束的基因中富含.
- 模拟表明,由洞穴中较小的人口规模加剧的遗传漂移足以解释增加的PTC频率.
- 表面体中pde6c的实验性突变回顾了与洞穴相关的特征.
- 洞穴种群中的高频PTC的一个子集与选择性扫描重叠,表明潜在的适应性作用.
结论:
- PTCs在产生功能丧失的表型和推动洞穴居住的墨西哥四动物的适应方面发挥着重要作用.
- 放松的进化约束和遗传漂移是导致洞穴种群中PTC积累的主要因素.
- 虽然漂移是主要的驱动因素,但特定的PTC可能会带来适应性优势,有助于地下生物的独特生物学.
相关概念视频
Nonsense-mediated mRNA Decay
10.5K
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
10.5K
Incomplete Dominance
21.2K
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
21.2K
Genetic Screens
4.9K
Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing genetic diseases and help them with early intervention, targeted therapy, and reproductive options.
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which...
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which...
4.9K
Gene Evolution - Fast or Slow?
7.0K
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...
7.0K
Mutations
79.1K
Overview
79.1K
Translation
14.5K
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Proteins are...
Translation Produces the Building Blocks of Life
Proteins are...
14.5K

