Numerical evaluation of changes in the cytoplasmic microtubule complex of C3H mouse cells by optical diffractometry and of changes in cell shape by fourier analysis

Abstract

MO mouse cells in culture on glass were treated with taxol, or nocodazole. or incubated at 4°C to alter their cytoplasmic microtubule complex (CMTC). From each treated group and from an untreated group, 30 cells stained with an antiserum against tubulin, were photographed under the photomicroscope, and negatives were analysed by optical diffractometry. Differences between groups of cells were tested by variance analysis. Phasecontrast micrographs of the same cells were used for Fourier analysis of cell shape. Both types of analyses provided numerical objective data about changes in the CMTC and in cell shape that were typical for the kind of treatment. We conclude that optical diffractometry of immunostained cells and Fourier analysis of cell shape are complementary to photomicroscopy for the study of the CMTC in cell populations cultured on an artificial substrate.Key terms: Cytoplasmic microtubule complex, optical diffractometry, Fourier analysis of cell shape, MO mouse cellsImmunocytochemistry is the method of choice to demonstrate the cytoplasmic microtubule complex (CMTC) (5) in cells spread on a n artificial substrate. In most cells immunocytochemistry has allowed at best a semiquantitative and interpretative evaluation of the CMTC (19). Optical diffractometry of morphological pictures allows a numerical evaluation that is objective and that permits statistical analysis.The diffraction pattern obtained by optical Fourier transform contains integrated information on the dimensions of structures, distances between them, and on their spatial arrangement. Since the diffraction pattern integrates the information from the whole analysed image, the signal-to-noise ratio may be higher than in the original image where regularities of the structure can be masked by random disorders. The radial distribution of light intensities contains information on the dimensions of structures and on distances between them; the angular distribution contains information on the predominant directions of structures.With a diffractometer coupled to a computer-based automatic detection system, a large number of pictures can be analysed and compared statistically. This method has been widely used in biology (18). Examples are screening of mitotic cells (ZO), automatic finding of metaphase chromosomes (13, cytology of cervical samples (22), analysis of cell structure (6), of collagen fibers in bone tissue (12,13), of the fine structure of arterial smooth muscle cells (211, and of myelin sheets (23).It is the purpose of the present investigation to see whether optical diffractometry can be used for quantitative and objective analysis of alterations of the CMTC in cells cultured on artificial substrate. Therefore, we have studied MO mouse cells from continuous cultures treated with agents that provoke known alterations of the CMTC, namely, taxol, nocodazole, and incubation at 4°C. Taxol leads to a n increased but unordered assembly 'Supported by the Kankerfonds van de Algemene Spa=-en Lijfrentekas, Brussels, Belgium and by the Polish Gover...

Aperiodic crystals in biology

“…For example, optical diffraction has been successfully employed as a tool for quantitative analysis of tissue speciments on the basis of illuminating previously obtained transparent micrographies by a laser beam, which is then diffracted to get the diffraction pattern [97]. The Fourier analysis of the cell shapes has been also reported by using this technique [98].…”