ホミニドにおける高ゲノム有害変異率
1Centre for the Study of Evolution and School of Biological Sciences, University of Sussex, Brighton, UK. A.C.Eyre-Walker@susx.ac.uk
Nature
|February 9, 1999
まとめ
人間は新しい有害な突然変異の高い割合を経験し,世代毎にゲノム当たり1.6以上で,タンパク質コード配列に影響を与えます. 自然選択は多くの種を排除しますが,この割合は低生殖率の種を抑制します.
科学分野:
- ゲノミクスゲノミクスとは
- 進化生物学の進化生物学について
- 分子生物学は分子生物学である.
背景:
- 人間のゲノム突然変異率は議論されている.
- 有害な突然変異の蓄積を理解することは,進化論の研究にとって極めて重要です.
研究 の 目的:
- ホミニドにおける有害な変異率を推定する.
- 自然選択がこれらの変異に与える影響を評価する.
主な方法:
- DNA配列解析を用いた分子アプローチを適用しました.
- ホミニドのタンパク質コード配列における選択的制約のレベルを調べた.
主要な成果:
- ヒトの血統系において,一世代あたりの二倍体毎に推定4.2のアミノ酸変異がある.
- これらの突然変異の少なくとも38%が自然選択によって排除されたことを決定しました.
- 1世代毎に二倍体ゲノムあたり1.6以上の新しい有害な変異を計算しました.
結論:
- タンパク質をコードする配列における有害な突然変異率は,人間にとって許容できる限界に近い.
- 有害な突然変異の相乗効果が発生する可能性があります.
- ホミニドの非典型的に低い選択的制約は,わずかに有害な突然変異の固定を示唆する.
関連する概念動画
Mismatch Repair
Overview
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 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 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...
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...
Mutations in Microorganisms
Mutations are heritable changes in an organism’s genome involving alterations in the base sequence of DNA or RNA. These changes can influence cellular processes and phenotypic traits, potentially transforming the unaltered wild type into a mutant form. Such changes, termed forward mutations, are pivotal in shaping the genetic diversity of organisms.RNA viruses exhibit the highest mutation rates due to the absence of robust proofreading mechanisms during genome replication. In contrast,...


