Pole reversal and the development of cell asymmetry during division in cryptomonad flagellates

Summary A unique form of cell division is reported for the cellsKomma caudata andCryptomonas ovata (Cryptophyceae). During cytokinesis, the posterior tail-like region of each daughter cell develops from the anterior region of the parental cell. This process, termed pole reversal, involves a major realignment in overall cell polarity as well as alterations to cytoplasmic and surface components. Pole reversal may be a consequence of flagellar apparatus transformation and reorientation during division, and pole reversal may facilitate the development of the asymmetric cell shape in daughter cells.