Farrington J E, Patel R, Ward W S
Oncology Center, Johns Hopkins University, Baltimore, Maryland.
Ann N Y Acad Sci. 1991;637:164-74. doi: 10.1111/j.1749-6632.1991.tb27309.x.
Hamster sperm DNA is packaged so tightly that it is the most highly condensed eukaryotic DNA known. Nevertheless, the sperm genome is also organized in a very specific fashion by two nuclear structures, the nuclear matrix and the nuclear annulus. The nuclear matrix organizes sperm DNA into loop domains approximately 46 Kb in length by specific attachment sequences. When the sperm nucleus is induced to decondense, the nuclear matrix almost completely dissipates, leaving only the nuclear annulus, a structure located at the implantation fossa within the nucleus. All the DNA remains anchored to the annulus during decondensation. Rotary shadowing transmission electron microscopy of isolated nuclear annuli retaining only a small portion of this anchored DNA suggests that the DNA is anchored to the annulus in a series of mini-loops, 5-10 Kb in length. These data support our previous suggestions that sperm DNA is organized in a very specific manner.
仓鼠精子DNA被紧密包装，是已知的真核生物中压缩程度最高的DNA。然而，精子基因组也通过两种核结构——核基质和核环，以非常特定的方式组织起来。核基质通过特定的附着序列将精子DNA组织成长度约为46千碱基对的环状结构域。当精子细胞核被诱导解聚时，核基质几乎完全消散，只留下核环，这是一种位于细胞核内植入窝处的结构。在解聚过程中，所有DNA仍锚定在核环上。对仅保留一小部分这种锚定DNA的分离核环进行旋转阴影透射电子显微镜观察表明，DNA以一系列长度为5-10千碱基对的小环形式锚定在核环上。这些数据支持了我们之前提出的精子DNA以非常特定的方式组织的观点。
