適応的収束の分子多様性について
Olivier Tenaillon1, Alejandra Rodríguez-Verdugo, Rebecca L Gaut
1Department of Ecology and Evolutionary Biology, University of California-Irvine, CA 92697, USA. olivier.tenaillon@inserm.fr
Science (New York, N.Y.)
|January 28, 2012
まとめ
有益な突然変異は,熱への細菌の適応を促す. 特定の遺伝子の標的が収束している一方で,他の多くの変異が高温で進化するEscherichia coliに貢献しています.
科学分野:
- 進化生物学の進化生物学について
- 微生物学 微生物学とは
- ゲノミクスゲノミクスとは
背景:
- 有益な突然変異を理解することは,進化の軌道を予測する鍵です.
- 実験的な進化は,適応メカニズムについての洞察を提供します.
研究 の 目的:
- 有益な突然変異の数と多様性を推定する.
- 高温への適応の遺伝的標的を特定するために,Escherichia coli.
主な方法:
- エシェリキア・コライ菌の115種を,2000世代間,42.2°Cで実験的に進化させた.
- 複製ごとに1つの進化した集団の全ゲノム配列決定.
- 変異を特定し分類するためのバイオ情報分析.
主要な成果:
- 600以上のサイトで1331の変異を特定しました.
- 低変異共有にもかかわらず,遺伝子,オペロン,機能複合体レベルで収束が観察されました.
- 高温への適応のための,未発見の主要な機能的標的.
結論:
- Escherichia coliの高温適応には,さまざまな有益な突然変異が含まれる.
- エピスタシスは適応的経路を大きく形成し,進化の異なる経路につながります.
- RNAポリメラーゼ複合体と終末因子rhoは,熱適応の主要な標的である.
関連する概念動画
01:54Convergent Evolution
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
01:28Diversity of Antigen Receptors
Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
02:37Gene 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.
01:20Applications of Molecular Taxonomy
Molecular taxonomy has revolutionized the understanding and classification of bacteria, providing precise insights into their diversity, evolutionary relationships, and ecological roles. By utilizing molecular techniques such as DNA sequencing and fingerprinting, researchers have made significant strides in various fields related to bacterial studies.Resolving Taxonomic AmbiguitiesMolecular taxonomy has been instrumental in distinguishing closely related bacterial species initially thought to...
02:16Genetics of Speciation
Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.
01:09Mutation, 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).