Cells abandon the spread or elongated shape characteristic of interphase and contract into a spherical morphology during mitosis.
[1] Sauer noticed that cells in mitosis rounded up to the apical, or luminal, surface of the columnar epithelium before dividing and returning to their elongated morphology.
Recent studies in the epithelia and epidermis of various organisms, however, show that mitotic cell rounding might serve several important functions.
[10][11] As a result, the surface tension and effective stiffness of the actin cortex increase as has been consistently observed in mitotic cells.
[10][11][15] In similar in vitro experiments, it was found that the threshold forces required to prevent mitosis are in excess of 100 nN.