marsupial Monodelphis domestica 的基因组揭示了在非编码序列中的创新
Tarjei S Mikkelsen1, Matthew J Wakefield, Bronwen Aken
1Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, Massachusetts 02142, USA. kersli@broad.mit.edu
Nature
|May 15, 2007
概括
灰色的,短尾的基因组为哺乳动物进化提供了洞察力. 这种有袋动物的基因组揭示了不同的染色体特征,并突出了转子子.
科学领域:
- 基因组学就是基因组学.
- 进化生物学 进化生物学
- 哺乳动物比较基因组学
背景情况:
- 灰色的短尾 (Monodelphis domestica) 是第一个被测序基因组的有袋动物物种.
- 与胎盘哺乳动物 (eutherians) 相比, marsupials 提供了一个独特的进化视角.
研究的目的:
- 为提供高质量的Monodelphis domestica的基因组序列草案.
- 分析基因组组织和转基因哺乳动物的进化模式.
- 为了比较鱼和鱼的基因组,以了解哺乳动物的进化创新.
主要方法:
- 全基因组测序的Monodelphis domestica. 这种动物.
- 马和eutherian基因组之间的比较基因组分析.
- 保存的非编码元素 (CNEs) 的识别和表征.
主要成果:
- 马染色体表现出支持基因组进化理论的特征,包括偏差基因转换和X染色体失活.
- 蛋白质编码基因创新是有限的,差异主要来自基因家族多样化.
- 大约20%的eutherian保存的非编码元素 (CNEs) 是新型的,是在metatherian-eutherian分歧之后的,其中许多来自可转移元素.
结论:
- possum 基因组为哺乳动物基因组的演变和功能提供了关键的见解.
- 可移植的元素是哺乳动物基因调节中的进化创新的重要驱动力.
- 非编码元素显示出比蛋白质编码基因更高的近期进化发明率.
相关概念视频
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.
Synteny and Evolution
John H. Renwick first coined the term “synteny” in 1971, which refers to the genes present on the same chromosomes, even if they are not genetically linked. The species with common ancestry tend to show conserved syntenic regions. Therefore, the concept of synteny is nowadays used to describe the evolutionary relationship between species.
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Gene Duplication and Divergence
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
Exon Recombination
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 has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
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.
Evolution of Microbial Genome
Microbial genome evolution is a highly dynamic process shaped by continual gene gain and loss across species and strains. This genomic flexibility allows microorganisms to adapt rapidly to environmental pressures and interactions with other organisms. Central to understanding this diversity is the distinction between the core and pan genomes.The core genome comprises the genes shared by all sampled strains of a species, representing essential functions needed for fundamental cellular processes.


