Tracking of microinjected DNA in live cells reveals the intracellular behavior and elimination of extrachromosomal genetic material
Tracking of microinjected DNA in live cells reveals the intracellular behavior and elimination of extrachromosomal genetic material
复制标题
DOI：
10.1093/nar/gki946
复制
发表时间：
2005-01-01
影响因子：
14.9
通讯作者：
Shigematsu, S
中科院分区：
文献类型：
--
作者：
Shimizu, N;Kamezaki, F;Shigematsu, S
我们在这里解决了一个基本问题：当染色体外 DNA 被置于细胞核或细胞质环境中时，它会如何表现以及它是如何被消除的？为此，我们追踪了活细胞中显微注射的 DNA 分子。在细胞质中，显微注射 DNA 的扩散以大小和线性依赖性方式受到抑制，可能是受到中间丝的抑制。随后 DNA 荧光信号迅速消失。在细胞核中，扩散也取决于分子的大小，并伴随着 DNA 的聚集。这种聚集可能是由于假定的 DNA 结合分子所致，该分子在 G(1) 期的水平很高。令人惊讶的是，注射的 DNA 可以穿过核膜并出现在细胞质中，这表明运输系统的存在。这种DNA的胞浆内行为和消除与直接注入细胞质的DNA明显不同。保留在细胞核中的 DNA 似乎是稳定的，并在细胞核中或细胞分裂后在细胞质中持续存在超过一个细胞周期。这些发现为多种染色体外遗传物质的行为和消除提供了新颖且基本的理解。
We here addressed the basic question, how does extrachromosomal DNA behave when it is placed in the nuclear or the cytoplasmic environment and how is it eliminated? To do this, we tracked microinjected DNA molecules in live cells. In the cytoplasm, the diffusion of microinjected DNA was inhibited in a size- and linearity-dependent manner, probably by the intermediate filament. This was followed by the rapid disappearance of the DNA fluorescent signal. In the nucleus, the diffusion was also dependent on the size of the molecule and was accompanied by the aggregation of the DNA. The aggregation may be due to a putative DNA-binding molecule, whose level is high during the G(1) phase. Surprisingly, the injected DNA could move across the nuclear membrane and appeared in the cytoplasm, which suggests the presence of a transport system. The intracytoplasmic behavior and the elimination of such DNA was obviously different from the DNA that was directly injected at the cytoplasm. The DNA remaining in the nucleus appeared to be stable and persisted in the nucleus or, after cell division, in the cytoplasm, for more than one cell cycle. These findings provide a novel and basic understanding of the behavior and elimination of a wide variety of extrachromosomal genetic material.