Eils R, Bertin E, Saracoglu K, Rinke B, Schröck E, Parazza F, Usson Y, Robert-Nicoud M, Stelzer E H, Chassery J M
Interdisciplinary Centre for Scientific Computing (IWR), Heidelberg, Germany.
J Microsc. 1995 Feb;177(Pt 2):150-61. doi: 10.1111/j.1365-2818.1995.tb03545.x.
This study demonstrates the use of Voronoi tessellation procedures to obtain quantitative morphological data for chromosome territories in the cell nucleus. As a model system, chromosomes 7 and X were visualized in human female amniotic fluid cell nuclei by chromosomal in situ suppression hybridization with chromosome-specific composite probes. Light optical serial sections of 18 nuclei were obtained with a confocal scanning laser fluorescence microscope. A three-dimensional (3-D) tessellation of the image volumes defined by the stack of serial sections was then performed. For this purpose a Voronoi diagram, which consists of convex polyhedra structured in a graph environment, was built for each nucleus. The chromosome territories were extracted by applying the Delaunay graph, the dual of the Voronoi diagram, which describes the neighbourhood in the Voronoi diagram. The chromosome territories were then described by three morphological parameters, i.e. volume, surface area and a roundness factor (shape factor). The complete evaluation of a nucleus, including the calculation of the Voronoi diagram, 3-D visualization of extracted territories using computer graphic methods and parameterization was carried out on a Silicon Graphics workstation and was generally completed within 5 min. The geometric information obtained by this procedure revealed that both X- and 7-chromosome territories were similar in volume. Roundness factors indicated a pronounced variability in interphase shape for both pairs of chromosomes. Surface estimates showed a significant difference between the two X-territories but not between chromosome 7-territories.
本研究展示了使用Voronoi镶嵌程序来获取细胞核中染色体区域的定量形态学数据。作为一个模型系统，通过使用染色体特异性复合探针进行染色体原位抑制杂交，在人类女性羊水细胞核中可视化了7号和X染色体。使用共聚焦扫描激光荧光显微镜获得了18个细胞核的光学连续切片。然后对由连续切片堆栈定义的图像体积进行三维（3-D）镶嵌。为此，为每个细胞核构建了一个由在图形环境中结构化的凸多面体组成的Voronoi图。通过应用Delaunay图（Voronoi图的对偶图，它描述了Voronoi图中的邻域）提取染色体区域。然后用三个形态学参数描述染色体区域，即体积、表面积和一个圆度因子（形状因子）。在Silicon Graphics工作站上对一个细胞核进行完整评估，包括Voronoi图的计算、使用计算机图形方法对提取区域进行三维可视化以及参数化，通常在5分钟内完成。通过该程序获得的几何信息表明，X染色体区域和7号染色体区域的体积相似。圆度因子表明这两对染色体在间期形状上存在明显差异。表面估计显示两个X染色体区域之间存在显著差异，但7号染色体区域之间没有差异。
