Panno J P
Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
Cytometry. 1988 May;9(3):195-200. doi: 10.1002/cyto.990090302.
An algorithm is described that is used to analyze the two-dimensional spatial symmetry of cell nuclei. The method provides two symmetry features: the symmetry index (SI), which estimates the precise spatial symmetry of a given chromatin component, Cn, and the quadrant symmetry index (QSI), which estimates the number of quadrants being occupied by Cn. A previous analysis is used to show that age-related change in Malpighian tubule nuclei from the adult housefly is associated with significant alterations in the spatial symmetry of low-, medium-, and high-density chromatin components (LDC, MDC, HDC). This included a seven-fold increase in the spatial symmetry of HDC and a shift in the symmetry profile (from highest to lowest degree of symmetry) from LDC-MDC-HDC to MDC-LDC-HDC. The increased spatial symmetry of HDC suggests that it occurs at new nuclear sites as the fly ages and that these sites are distributed over approximately 60% of the chromosome population.
本文描述了一种用于分析细胞核二维空间对称性的算法。该方法提供了两个对称特征：对称指数（SI），用于估计给定染色质成分Cn的精确空间对称性；象限对称指数（QSI），用于估计Cn占据的象限数量。先前的一项分析表明，成年家蝇马尔皮基氏管细胞核中与年龄相关的变化与低、中、高密度染色质成分（LDC、MDC、HDC）的空间对称性显著改变有关。这包括HDC的空间对称性增加了七倍，以及对称分布从LDC-MDC-HDC转变为MDC-LDC-HDC（从最高对称度到最低对称度）。HDC空间对称性的增加表明，随着苍蝇年龄的增长，它出现在新的核位点上，并且这些位点分布在大约60%的染色体群体上。
