Ward W S
Division of Urology, Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903-0019.
Biol Reprod. 1993 Jun;48(6):1193-201. doi: 10.1095/biolreprod48.6.1193.
In the four decades since the discovery of the basic structure of the DNA double helix, researchers have been investigating the more dynamic tertiary structures that DNA assumes in the various forms of chromatin. The tertiary structure of DNA is important because it is directly related to the function of the genome: for the cell to access the information that is present in the genome accurately and efficiently, the DNA must be in an organized form. This paper reviews the recent work on one particular enigmatic structural form of eukaryotic DNA, that of the highly condensed spermatozoa. Based on the literature and on recently completed experiments in the field, a new model for DNA packaging in sperm nuclei is presented. In this model, each individual DNA loop domain in the sperm chromatin is condensed into a toroid-shaped structure termed the DNA loop doughnut.
自发现DNA双螺旋的基本结构以来的四十年里，研究人员一直在研究DNA在各种染色质形式中呈现的更具动态性的三级结构。DNA的三级结构很重要，因为它与基因组的功能直接相关：为了使细胞准确、高效地获取基因组中存在的信息，DNA必须处于一种有组织的形式。本文综述了关于真核生物DNA一种特别神秘的结构形式——高度浓缩精子的最新研究工作。基于该领域的文献和最近完成的实验，提出了一种精子核中DNA包装的新模型。在这个模型中，精子染色质中的每个单独的DNA环结构域被浓缩成一种称为DNA环甜甜圈的环形结构。
