有害突变之间的干扰有利于有限种群中的性别和重组
Peter D Keightley1, Sarah P Otto
1Institute of Evolutionary Biology, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, UK. keightley.nature2006@spambob.net
Nature
|September 8, 2006
概括
性和重组,对进化至关重要,是由背景选择解释的. 这一过程增强了基因变异,改善了适应性和清除有害突变,特别是在较大的群体中.
科学领域:
- 进化生物学 进化生物学
- 人口遗传学 人口遗传学
背景情况:
- 性和重组是广泛的进化现象.
- 解释它们的适应优势一直是进化生物学中长期存在的挑战.
- 之前的理论侧重于适应性替代和穆勒杆,以基于突变率和种群规模的限制.
研究的目的:
- 调查背景选择在推动性别和重组的进化中的作用.
- 阐明重组提供随机优势的机制.
- 为性繁殖的流行提供一个强有力的解释.
主要方法:
- 影响性别和重组频率的跟踪修饰基因.
- 分析背景选择对遗传变异和适应的影响.
- 在有限种群中研究Hill-Robertson效应.
主要成果:
- 背景选择为性别和重组提供了一个随机优势,随着人口规模的增加而增加.
- 由于Hill-Robertson效应,低的重组水平降低了有效种群规模和遗传变异.
- 性和重组揭示了隐藏的遗传变异,改善了适应性和清除有害突变.
结论:
- 背景选择为重组的进化优势提供了一个广泛适用的解释.
- 这种机制是强大的,并且在很大程度上独立于有害基因之间的表皮相互作用.
- 这些发现解释了人口中昂贵的性和重组的传播.
相关概念视频
Mismatch Repair
Overview
Mutation, Gene Flow, and Genetic Drift
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).Mechanisms of Genetic VariationThe original sources of genetic variation are mutations,...
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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...
Mismatch Repair
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
Gene Conversion
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...
Crossing Over
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, duplicated...


