相关实验视频
Updated: Jun 23, 2026

12:19
Analysis of Cell Cycle Position in Mammalian Cells
Published on: January 21, 2012
通过基因重组调节的B细胞发育:通过与膜结合的D mu蛋白阻止成熟,并选择DH元素读取框架
1Institute for Genetics University of Cologne Federal Republic of Germany.
Cell
|April 5, 1991
概括
免疫球蛋白基因重新排列首选使用一个读取 (RF1) 由于对停止编码子和截断蛋白的表达的反选择. 这种偏见是早期确立的,而不是通过抗原选择.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 免疫球蛋白重链可变区域 (VH-DH-JH) 基因重组对B细胞发育至关重要.
- 多样性 (DH) 和结合 (JH) 基因段的结合发生在可变的断点上.
- 在DH-JH重新排列过程中,已经观察到特定读取 (RF1) 的首选使用.
研究的目的:
- 调查在小鼠免疫球蛋白重链基因重排序过程中偏好阅读框架使用背后的机制.
- 为了确定抗原的细胞选择是否影响读取偏差.
- 阐明不同读取在B细胞分化中的作用.
主要方法:
- 对生产性地重新排列的小鼠VH-DH-JH基因的分析.
- 通过同源重组利用Mu链中被破坏的膜外的B细胞.
- 评估截断的mu链 (D mu蛋白) 表达对B细胞分化的影响.
主要成果:
- 在读取1 (RF1) 中,DH元件被优先使用,尽管可变的重组断点.
- 读取3 (RF3) 由于停止编码子而被反选择.
- 读取2 (RF2) 导致截断的D mu蛋白的表达,这表明分化停止.
- 促进DH-JH在同源序列中加入,进一步强制使用RF1.
结论:
- 在DH-JH重新排列期间阅读使用的偏差在B细胞发育早期被定量确立.
- 这种偏差主要是由内在的分子机制驱动的 (停止子反选择,截断蛋白质效应),而不是由抗原驱动的外在细胞选择.
- 这些发现提供了关于免疫球蛋白基因组合和B细胞分化的调节的见解.
相关概念视频
Negative Regulator Molecules
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
The 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...
Mitogens and the Cell Cycle
Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
The 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...
Molecular 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...

