単細胞分析は,mTDNAの文脈依存の細胞レベルの選択を明らかにする
Anna V Kotrys1,2, Timothy J Durham1,2, Xiaoyan A Guo1,2
1Howard Hughes Medical Institute and Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Nature
|April 24, 2024
まとめ
ミトコンドリアDNA (mtDNA) ヘテロプラズミーのシフトは,分裂する細胞で漂流ではなく選択によって引き起こされる. 環境条件は,mtDNA変異が細胞の健康に有益であるか有害かを決定し,ヘテロプラズミーのレベルに影響を与えます.
科学分野:
- 細胞生物学
- 遺伝学
- 生物化学
背景:
- 細胞内のワイルド型と変異性ミトコンドリアDNA (mtDNA) の共存であるヘテロプラズミーは,発達,病気,老化中に動的に変化します.
- ヘテロプラズミーのシフトを誘発するメカニズム― 選択対漂流と細胞対細胞レベル― は未だに十分に理解されていない.
研究 の 目的:
- 細胞分裂におけるヘテロプラズミーの動態を調査する.
- 選択や漂流がヘテロプラズミーのレベルを形作るか否かを判断する.
- 選択が細胞レベルか細胞内レベルで作用するかを理解する.
主な方法:
- 標的型変異に対して精密なmtDNA塩基編集 (DdCBE) を利用した.
- SCI-LITE (標的表現を調査するために利用された単細胞組合せインデックス) を採用し,超高スループット単細胞ヘテロプラズミーの追跡を行っています.
- 同義または非同義の複合I mtDNA変異を持つエンジニアリングされた細胞.
主要な成果:
- 非同義的なmtDNA変異は除去され,同義的な変異は標準的な細胞培養に維持され,ドリフトよりも選択が優位であることを示した.
- 単細胞のヘテロプラズミーと祖先の追跡は,集団のシフトにもかかわらず,安定した系統のヘテロプラズミーを明らかにし,選択が細胞の適性に作用することを示唆した.
- 細胞は,コンプレックスI mtDNAヘテロプラズミーの高いレベルを特定の環境で蓄積し,コンプレックスI活動の喪失はフィットネス上の利益をもたらした.
結論:
- 細胞分裂では,単純なドリフトではなく,選択が集団ヘテロプラズミーを形作る.
- 選択は細胞の適性レベルで作用し 細胞環境の影響を受けます
- 非同義性 mtDNA ヘテロプラズミーの細胞健康への影響は文脈に依存し,環境条件に基づいて有害から有益まで様々である.
関連する概念動画
Animal Mitochondrial Genetics
7.6K
Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
7.6K
Evolutionary Relationships through Genome Comparisons
5.7K
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
5.7K
Comparing Mitochondrial, Chloroplast, and Prokaryotic Genomes
12.4K
The present-day mitochondrial and chloroplast genomes have retained some of the characteristics of their ancestral prokaryotes and also have acquired new attributes during their evolution within eukaryotic cells. Like prokaryotic genomes, mitochondrial and chloroplast genomes neither bind with histone-like proteins nor show complex packaging into chromosome-like structures, as observed in eukaryotes. Unlike mitotic cell divisions observed in eukaryotic cells, mitochondria and chloroplasts...
12.4K
Non-nuclear Inheritance
21.5K
Most DNA resides in the nucleus of a cell. However, some organelles in the cell cytoplasm—such as chloroplasts and mitochondria—also have their own DNA. These organelles replicate their DNA independently of the nuclear DNA of the cell in which they reside. Non-nuclear inheritance describes the inheritance of genes from structures other than the nucleus.
21.5K
Gene Evolution - Fast or Slow?
7.1K
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...
7.1K
Export of Mitochondrial and Chloroplast Genes
3.7K
A eukaryotic cell can have up to three different types of genetic systems: nuclear, mitochondrial, and chloroplast. During evolution, organelles have exported many genes to the nucleus; this transfer is still ongoing in some plant species. Approximately 18% of the Arabidopsis thaliana nuclear genome is thought to be derived from the chloroplast’s cyanobacterial ancestor, and around 75% of the yeast genome derived from the mitochondria’s bacterial ancestor. This export has occurred...
3.7K


