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In Vivo Modeling of the Morbid Human Genome using Danio rerio
Published on: August 24, 2013
人类基因组中蛋白质编码基因上的自然选择
Carlos D Bustamante1, Adi Fledel-Alon, Scott Williamson
1Department of Biological Statistics and Computational Biology, 101 Biotechnology Building, Cornell University, Ithaca, New York 14853, USA. cdb28@cornell.edu
Nature
|October 21, 2005
概括
自然选择显著塑造了人类的分子进化,许多基因显示出快速的氨基酸进化或纯化选择的证据. 这项研究揭示了不同生物过程中选择模式的变化.
科学领域:
- 进化生物学是进化的生物学.
- 分子进化是分子进化的过程.
- 基因组学就是基因组学.
背景情况:
- 将物种内部的DNA多态性与物种间的分歧进行比较,有助于识别分子适应和净化选择.
- 物种表现出不同程度的分子进化,由弱负和正达尔文选择驱动.
研究的目的:
- 研究自然选择对人类近期分子进化的影响.
- 为了对比人类的编码序列多态化模式与人类和黑猩猩之间的差异.
主要方法:
- 在39个人类中对超过11000个基因的编码序列的直接测序.
- 分析人类的DNA多态性和人类和黑猩猩物种之间的差异.
主要成果:
- 发现了强有力的证据,证明自然选择塑造了人类最近的分子进化.
- 304个位点 (9.0%) 显示出快速的氨基酸进化,表明了积极的选择.
- 813个位点 (13.5%) 显示缺乏氨基酸差异,表明负或平衡选择.
结论:
- 选择基因的分布在生物过程和分子功能之间有所不同.
- 转录因子显示出过多的快速进化的基因.
- 细胞骨蛋白在人类中表现出高多态性,人类和黑猩猩之间的差异较低.
相关概念视频
From DNA to Protein
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...
Gene Evolution - Fast or Slow?
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...
Genome Size and the Evolution of New Genes
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.
Multi-species Conserved Sequences
Next-generation sequencing technologies have created large genomic databases of a variety of animals and plants. Ever since the human genome project was completed, scientists studied the genome of primates, mammals, and other phylogenetically distant living beings. Such large-scale studies have provided new insights into the evolutionary relationship between organisms.
Although the genome of each species varies greatly from each other, a few sequences are highly conserved. Such conserved DNA...
Although the genome of each species varies greatly from each other, a few sequences are highly conserved. Such conserved DNA...
Genome Size and the Evolution of New Genes
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.
Gene Evolution - Fast or Slow?
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...

