Marinelli F, Falcieri E, Squarzoni S, Del Coco R, Zini N, Manzoli L, Maraldi N M
Istituto di Citomorfologia Normale e Patologica CNR, Bologna; Italy.
Biol Cell. 1990;70(3):107-19. doi: 10.1016/0248-4900(90)90366-b.
The complex organization of the interphase nucleus can be analyzed, by way of thin sectioning and also freeze-fracture. This approach has previously been utilized in association with image analysis to quantitatively describe the organization of isolated rat liver nuclei and nuclear matrices. The main nuclear domains which, in section, present marked differences due to their electron-density, can be identified in replicas with more complex procedures, based on the quantitative evaluation of the number of particles per unit area and mainly by using image analysis. A quantitative analysis of the nuclear substructures has been performed by way of image analysis on in situ nuclei of freeze-fractured cells presenting marked differences in the heterochromatin quantity, such as hepatocytes and lymphocytes. The replicated nuclear particles have been classified according to their diameter and the obtained histograms have been quantitatively evaluated. The nuclear domains, heterochromatin, interchromatin, nucleolus, present characteristic ratios among the three main classes of particles; that is, ribonucleoproteins, solenoid filaments and solenoid fibre aggregates. The typical patterns of the nuclear domains can be further stressed by selecting a single class of particles and by examining its topographic localization. While interchromatin and nucleolar domains present a similar quantitative pattern in hepatocytes and lymphocytes, the heterochromatin of lymphocytes contains a significative higher percentage of solenoid aggregates than that of hepatocytes.
通过薄切片以及冷冻断裂的方法，可以分析间期细胞核的复杂组织结构。此前，这种方法已与图像分析相结合，用于定量描述分离的大鼠肝细胞核和核基质的组织结构。在切片中，由于电子密度不同，主要的核区域呈现出明显差异，基于对单位面积颗粒数量的定量评估，主要通过图像分析，采用更复杂的程序可在复制品中识别这些区域。通过图像分析，对冷冻断裂细胞原位核进行了定量分析，这些细胞在异染色质数量上存在明显差异，如肝细胞和淋巴细胞。复制的核颗粒已根据其直径进行分类，并对所得直方图进行了定量评估。核区域、异染色质、染色质间区域、核仁，在三类主要颗粒（即核糖核蛋白、螺线管丝和螺线管纤维聚集体）之间呈现出特征性比例。通过选择单一类别的颗粒并检查其拓扑定位，可以进一步突出核区域的典型模式。虽然染色质间区域和核仁区域在肝细胞和淋巴细胞中呈现出相似的定量模式，但淋巴细胞的异染色质中螺线管聚集体的百分比明显高于肝细胞。
