同様の論理を持つ代替トランスクリプション回路の進化
Annie E Tsong1, Brian B Tuch, Hao Li
1Department of Biochemistry & Biophysics, University of California San Francisco, San Francisco, California 94143-2200, USA.
Nature
|September 29, 2006
まとめ
遺伝子規制の進化は,生命の多様性を駆り立てている. 研究者は酵母の交配規則の変化を追跡し,活性化から抑制へのスイッチが回路の機能を維持することを発見しました.
科学分野:
- 進化生物学の進化生物学について
- 遺伝学 遺伝学とは
- 分子生物学は分子生物学である.
背景:
- 遺伝子調節の進化は生物多様性に寄与する.
- DNA結合タンパク質を含む複合転写回路は,真核生物全体で保存されている.
- これらの回路は,酵母における交配プロセスを調節する役割を果たします.
研究 の 目的:
- アスコミケト酵母菌の系統における交配を調節する特定の組み合わせ転写回路の進化を分析する.
- 陽性 (活性化) から陰性 (抑制) 遺伝子調節への移行を理解する.
- この進化的転換期におけるシス・およびトランス・レギュレーション要素の特定の変化を特定する.
主な方法:
- 異なった酵母種間の遺伝子調節の比較分析.
- 保存された配列特異性DNA結合タンパク質の識別.
- 関連酵母種を調査することによって,規制要素の連続的な変化の引き算.
主要な成果:
- 交配遺伝子のグループは,進化の過程でアクティベーターから抑制器のコントロールに移った.
- 規制メカニズムの変更 (ポジティブからネガティブに) に関わらず,回路の論理出力は一貫したままでした.
- シス・およびトランス・レギュレーション要素の特定の,連続的な変化が特定されました.
結論:
- この研究は,酵母における遺伝子調節回路の進化の経路を明らかにしている.
- 発見は,機能的な出力を維持しながら,規制メカニズムがどのように変化するかを示しています.
- この移行を容易にし,フィットネスの障壁を克服する特定の分子変化が強調されました.
関連する概念動画
Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
Combinatorial Gene Control
Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression.
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
Gene 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.
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
Neural Circuits
Neural circuits and neuronal pools are two of the main structures found in the nervous system. Neural circuits are networks of neurons that work together to carry out a specific task or process. They consist of interconnected neurons and glial cells, which provide structural and metabolic support.
Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that...
Neuronal pools are collections of nerve cells with similar functions and interact through chemical and electrical signals. These pools include both interneurons (the central neural circuit nodes that...


