Orientation of mitosis of fibroblasts is determined in the interphase

Time-lapse films of the cultures of mouse L fibroblasts have been analyzed to find out the angles between the direction of the big axis of interphase nucleus before mitosis and the direction of the mitotic furrow in the same cell. In 41 out of 51 mitoses this angle has been found to be more than 60 degrees . Thus, the orientation of mitotic furrows depends on the internal polarity of the cell before mitosis.