间期染色体的软X射线光刻研究。

Soft x-ray lithographic studies of interphase chromosomes.

作者信息

Manuelidis L, Sedat J, Feder R

出版信息

Ann N Y Acad Sci. 1980;342:304-25. doi: 10.1111/j.1749-6632.1980.tb47230.x.

DOI:10.1111/j.1749-6632.1980.tb47230.x

Abstract

Soft x-ray absorption lithograph patterns of purified interphase human nuclei and chromosome arrays, imaged on PMMA resists, were examined by scanning EM. The patterns obtained were compared to those utilizing more conventional sources, including transmission EM, scanning EM, high voltage EM, and various light microscopic techniques. The x-ray resist images revealed orderly arrays of absorption profiles in the 3-dimensional specimen with both mild and more extensive developments of the resist. Dense chromatin at the edge of interphase nuclei revealed aligned periodic peaks on the order of 2200 A diameter, with substructure. The periodicity and alignment of interphase chromosomes were entirely consistent with birefringent data on nuclei indicating a high degree of 3-dimensional order. This degree of 3-dimensional order was observed in nuclei containing essentially DNA and histones with only very few other minor (probably structural) proteins. Sonication and nuclease treatment to disperse interphase chromosomes revealed similar absorption periodicities in individual chromosome fibers. Analysis of x-ray absorption profiles thus appears to offer significant new insights into the ordered structure of these defined biological specimens.

摘要

通过扫描电子显微镜（SEM）对在聚甲基丙烯酸甲酯（PMMA）抗蚀剂上成像的纯化间期人细胞核和染色体阵列的软X射线吸收光刻图案进行了检查。将获得的图案与使用更传统光源（包括透射电子显微镜、扫描电子显微镜、高压电子显微镜和各种光学显微镜技术）得到的图案进行了比较。X射线抗蚀剂图像显示，在三维样本中，随着抗蚀剂的轻度和更广泛显影，吸收轮廓呈现出有序排列。间期细胞核边缘的致密染色质显示出直径约为2200埃的对齐周期性峰值，并具有亚结构。间期染色体的周期性和排列与细胞核的双折射数据完全一致，表明具有高度的三维有序性。在基本上只含有DNA和组蛋白以及极少数其他次要（可能是结构性）蛋白质的细胞核中观察到了这种三维有序程度。超声处理和核酸酶处理以分散间期染色体，在单个染色体纤维中显示出类似的吸收周期性。因此，对X射线吸收轮廓的分析似乎为这些特定生物样本的有序结构提供了重要的新见解。