原核生物とハイムダラーキアの間の広範な横向遺伝子転送は,真核生成の間に密接な関連性を示唆している
1Institute Pasteur, Microbiology Department Paris France.
mLife
|September 2, 2025
まとめ
ユカリアのヘイムダラーキアの起源は疑問視されている. 分析によると,ユーカリアとアスガルドの古生物は,広範囲にわたる遺伝子転送によって共進化し,ユーカリオゲネシスと古生物の多様化に大きく影響した.
科学分野:
- 微生物学
- 進化生物学
- ゲノミクス
背景:
- 2つの領域の枠組みでは,ユーカリアはホダルカイアルの姉妹であるヘイムダルカイアから生まれたと提案しています.
- アスガルドの古生物の中でユカリアの系統的配置は議論の余地がある.
研究 の 目的:
- アスガルドの古生物に対する ユカリアの遺伝的位置を再評価する
- ユカリオゲネシスと古代生物の進化における遺伝子移転の役割を調査する.
主な方法:
- 個々のタンパク質マーカーツリーの遺伝子解析
- 古代生物と原核生物の間の遺伝子転送パターンの調査.
主要な成果:
- ユカリアは,個別の遺伝子ツリーでホダルカイアや他のヘイムダルカイアと一貫して姉妹ではない.
- Crenarchaeota/Korachaeota から Njordarchaeales への大規模な遺伝子転送が観察されました.
- アスガルドのアルカイア全体に ユカリアとユカリオトのシグネチャータンパク質の不均一な分布
結論:
- 系統遺伝子の不一致は,原核生物とアスガルド古生物の間で広範囲にわたる双方向性遺伝子の移転を示唆する.
- 同進化はエウカリオゲネシスと アスガルドの古生物の多様化において重要な役割を果たした.
- ユカリアの起源は 特定の考古学的なグループとの 単純な姉妹関係よりも複雑である.
関連する概念動画
Horizontal Gene Transfer
125
Horizontal gene transfer (HGT) is a process where genetic material moves between organisms within the same generation, unlike vertical gene transfer, which occurs from parent to offspring. HGT plays a crucial role in microbial evolution, adaptation, and survival, particularly in shared environments like the human gut.Mobile genetic elements such as plasmids, prophages, integrons, insertion sequences, and transposons facilitate this process. HGT occurs through three primary mechanisms:...
125
Types of Genetic Transfer Between Organisms
29.3K
Genetic transfer occurs when genetic information is passed from one organism to another. It occurs via two mechanisms: vertical gene transfer and horizontal gene transfer. Vertical gene transfer occurs when genetic information is transferred from one generation to the next, which happens much more frequently than horizontal gene transfer. Both sexual and asexual reproduction are forms of vertical gene transfer, where one or more organisms pass some or all of their genome onto their progeny.
29.3K
Export of Mitochondrial and Chloroplast Genes
3.8K
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...
3.8K
Genome Size and the Evolution of New Genes
8.3K
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
8.3K
Eukaryotic Evolution
36.4K
The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
36.4K
Three-Domain System of Life
216
Ribosomal RNA (rRNA) sequence analysis revealed three distinct groups of cells: eukaryotes, bacteria, and archaea. In 1978, Carl R. Woese proposed the concept of domains, a taxonomic level above kingdoms, to differentiate these groups. He suggested that archaea and bacteria, despite their similar appearance, represent separate domains. Domains differ in rRNA, membrane lipid structure, transfer RNA, and antibiotic sensitivity.In this classification, animals, plants, and fungi belong to the...
216


