[An analysis of the centriole orientation in tissue culture cells]

A mathematical description of random orientation of centrioles with respect to the plane has been suggested for two modes of experimental procedure: a) all the centrioles in a given volume are taken into account; b) all the centrioles crossing an ultrathin section are accounted. In the former case the function of distribution does not depend on the length of the centrioles. Histograms of the distribution of centriolar length projections on the plane of the section have been obtained. These histograms are compared with those obtained for centrioles in mitotic pig kidney embryo cells (PE-cells). Tables of credible occurrence intervals for "nearly perpendicular" (the angle is tipped to the substrate plane by over 74 degrees) and for "nearly parallel" (the angle is tipped to the substrate plane by less than 12 degrees) centrioles in different samplings are adduced.