Ward W S
Division of Urology, Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903.
J Cell Biochem. 1994 May;55(1):77-82. doi: 10.1002/jcb.240550109.
The tertiary structure of the DNA that makes up the eukaryotic genome is remarkably plastic, taking many different forms in response to the different needs of the cell. During the cell cycle of one cell, the DNA is replicated, reorganized into mitotic chromosomes, and decondensed into interphase chromatin. Within one cell at any given point in time, the chromatin is divided into hetero- and euchromatin reflecting active and inactive states of the DNA. This organization varies within one organism since different parts of the genome are active in different cell types. This article focuses on the most dramatic cell-type-specific DNA organization, that found in spermatozoa, in which the entire genome is reorganized into an inactive state that is more highly condensed than mitotic chromosomes. This unique example of eukaryotic DNA organization offers some interesting clues to the still unanswered questions about the role that the three-dimensional packaging of DNA plays in its function.
构成真核生物基因组的DNA三级结构具有显著的可塑性，会根据细胞的不同需求呈现出多种不同的形式。在一个细胞的细胞周期中，DNA会进行复制，重新组织形成有丝分裂染色体，然后解聚成间期染色质。在任何给定时间的一个细胞内，染色质被分为异染色质和常染色质，反映了DNA的活跃和非活跃状态。由于基因组的不同部分在不同细胞类型中是活跃的，这种组织方式在一个生物体中会有所不同。本文重点关注最显著的细胞类型特异性DNA组织，即精子中的DNA组织，其中整个基因组被重新组织成一种比有丝分裂染色体更为高度浓缩的非活跃状态。这种真核生物DNA组织的独特例子为关于DNA三维包装在其功能中所起作用的一些尚未解答的问题提供了一些有趣的线索。
