概括
人类胎儿环球蛋白基因G 玛和A 玛起源于大约3400万年前的一次5千千倍的并联重复事件. 这些基因之间的基因转换大约发生在100万年前,这表明多基因家族的复杂进化动态.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 进化生物学 进化生物学
背景情况:
- 人类基因组包含具有复杂进化历史的多基因家族.
- 胎儿的全球蛋白基因 (G gamma和A gamma) 在发育过程中对氧气运输至关重要.
研究的目的:
- 阐明人类胎儿球蛋白基因集群的进化起源和机制.
- 在多基因家族中建模复制和基因转换的过程.
主要方法:
- 含有G gamma和A gamma基因的11.4 kb区域的DNA测序.
- 进行比较序列分析以确定重复和分歧.
- 遗传学分析以估计重复和基因转换事件的时间.
主要成果:
- 确定了一个5kB的双重复制,包括G gamma和A gamma基因.
- 估计最初的重复事件发生在3400万年前.
- 由于100万年前的基因转换,在1.5kb区域观察到近似性,可能涉及重复的二核酸序列.
结论:
- 胎儿球蛋白基因集群通过复制和基因转换的循环进化.
- 基因转换,可能由重复元素介导,在维护多基因家族内的序列身份方面发挥着重要作用.
- 这些进化过程在其他多基因家族的进化中可能是常见的.
相关概念视频
Gene Families
Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Genomic Imprinting and Inheritance
Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
Genome Copying Errors
DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a long stretch of wrong bases may get added to the daughter strands. If the errors are left unchecked, cells might accumulate several mutations that might endanger their survival. Therefore, the copying errors are checked and repaired at three levels.
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.
Duplication of Chromatin Structure
The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
Chromosome Duplication
The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...


