関連する実験動画
Updated: May 12, 2026
07:47
Microscopy of Fission Yeast Sexual Lifecycle
Published on: March 9, 2016
芽生える酵母菌におけるミトーシスのフィードバック制御
1Program in Cell Biology, University of California, San Francisco 94143-0444.
Cell
|August 9, 1991
まとめ
研究者は,芽生えた酵母変異体を研究することによって,重要な細胞サイクル制御を特定しました. これらのミトス停止欠陥 (MAD) 変異体は,早期の細胞分裂を防止し,正確な染色体分離を確保する重要なフィードバックメカニズムを明らかにします.
科学分野:
- 細胞生物学 細胞生物学
- 遺伝学 遺伝学とは
- 分子生物学は分子生物学である.
背景:
- 細胞サイクルの進行は,遺伝物質の正確な複製と分離を確保するために厳格に規制されています.
- 重要なチェックポイントは,すべての染色体が適切に並べられ,スパインドルに付着するまで,細胞がミトーシスを退けるのを防ぐ.
研究 の 目的:
- スピンドルの組立が不完全であるとき,ミトーシス中の細胞を停止するフィードバック制御メカニズムを調査する.
- このミトの停止プロセスに欠陥のある突然変異体を特定し,特徴づけること.
主な方法:
- 発芽中の酵母変異体の抗微小管薬ベノミールに敏感な単離.
- ベノミールと細胞サイクル進行に対する反応に焦点を当てた,ミトス停止欠陥 (マッド) 変異体の特徴.
- MAD2遺伝子のクローニングとその機能の分析.
主要な成果:
- ミトーシス停止欠陥 (マッド) 変異種が特定され,ミトーシスを早めに終了し,ベノミルで治療すると死亡します.
- これらの突然変異体がミトスの退出に対するフィードバック制御に欠陥があることが実証されました.
- クローンされたMAD2,生存に不可欠な遺伝子,推定カルシウム結合タンパク質をコードする.
結論:
- MAD2遺伝子製品は,ミトーシスからの脱出を制御するフィードバック制御において重要な役割を果たします.
- この制御の欠陥は,ミトスの破滅と細胞死につながる.
- フィードバックメカニズムは,細胞サイクルイベントの調整とゲノム安定性の維持に不可欠です.
関連する概念動画
01:28Yeast Signaling
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
02:11The Cell Cycle Control System
The cell cycle is an organized set of events that leads the cell to divide into two daughter cells, each containing chromosomes identical to the parent cell. It is the cell cycle that leads to the formation of an entire organism from a single-cell zygote. Besides, cell division also functions in the renewal or repair of tissues in adult multicellular eukaryotes. For example, in the bone marrow, the stem cells divide to form new blood cells. Although essential for several functions, cell...
02:36Cells Coordinate Growth and Proliferation
Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...
02:02Meiosis II
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
01:28The Cell Cycle Control System
The cell cycle regulation directs how a cell proceeds from one phase to the next and begins mitosis. The cell cycle control system includes intracellular regulatory molecules and external triggers. They provide "stop" or "advance" signals and operate at specific cell cycle stages termed checkpoints to ensure that a particular process is completed before the cell advances to the next phase.
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and function at the cell...
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and function at the cell...
01:27Molecular Factors Affecting Cell Division
Several external and internal factors influence the initiation and inhibition of cell division. For instance, the death of nearby cells or the release of human growth hormone (hGH) promotes cell division. In contrast, lack of hGH or crowding of cells can inhibit cell division.
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...