ニューロスペーラの昼夜システムにおける相互接続されたフィードバックループ
1Department of Genetics, Dartmouth Medical School, Hanover, NH 03755-3844, USA.
まとめ
Neurospora crassaの昼間時計は,FRQとホワイトカラー1 (WC-1) のタンパク質を含む相互接続されたフィードバックループを使用しています. この二重ループシステムは,生物種間で潜在的に保存されるメカニズムである昼夜リズムの強度と安定性を高めます.
科学分野:
- シルカディアン生物学
- 分子遺伝学 分子遺伝学
- ミコロジー 菌類学
背景:
- Neurospora crassaの昼夜時計は,重要なタンパク質の相互作用に依存しています.
- ホワイトカラー1 (WC-1) は,転写活性化剤であり,陽性時計要素である.
- wc-1トランスクリプトは非リズム的な安定状態プールから発現し,トランスクリプション後の調節を示唆しています.
研究 の 目的:
- Neurospora crassaの昼間時計におけるFRQとWC-1の調節作用を調査する.
- サーカディアン・システム内のフィードバック・ループの形成と機能を解明する.
- シルカディアンタイムリングにおける相互接続されたループの保存を調査する.
主な方法:
- 野生型および変異株におけるWC-1発現パターンの分析.
- FRQ発現がWC-1合成に与える影響を調査する.
- ドロソフィラ・メラノガスターとマウスモデルにおける昼夜システムとの比較分析.
主要な成果:
- WC-1は非リズム的なwc-1トランスクリプトにもかかわらずリズム的に発現し,トランスクリプション後の制御を示しています.
- frqの変異は,WC-1レベルと周期性に影響する.
- FRQは8時間の遅延でWC-1合成を正に調節し,第2のフィードバックループを形成します.
結論:
- FRQはニューロスポラクロックで二重の役割を果たし,リズムに寄与します.
- FRQとWC-1を含む相互接続されたフィードバックループは,昼間システムの強度と安定性を高めます.
- 相互に絡み合ったループは,様々な生物における昼夜時刻の維持のための保存されたメカニズムを表す可能性があります.
さらに関連する動画
関連する概念動画
Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
Positive and Negative Feedback Loops
Animal organs and organ systems constantly adjust to internal and external changes through a process called homeostasis ("steady state"). Examples of these changes include regulation of the level of glucose or calcium in the blood or internal responses to external temperatures. Homeostasis requires maintaining an internal dynamic equilibrium:
Cell Signaling Feedback Loops
Positive and negative feedback loops are crucial for regulating biological signaling systems. These feedback loops are processes that connect output signals to their inputs.
Negative feedback loops
Most signaling systems have negative feedback loops that can perform different functions such as output limiter, and adaptation.
Output limiter
Upon receiving an input signal, the cellular response rapidly increases until a threshold is reached. Beyond this threshold, a negative feedback loop...
Negative feedback loops
Most signaling systems have negative feedback loops that can perform different functions such as output limiter, and adaptation.
Output limiter
Upon receiving an input signal, the cellular response rapidly increases until a threshold is reached. Beyond this threshold, a negative feedback loop...
Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
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...


