Department of Genetics and Developmental Biology, Institut Curie, F-75248 Paris, France.
Dev Cell. 2013 Aug 12;26(3):250-65. doi: 10.1016/j.devcel.2013.07.005.
Abscission is the last step of cytokinesis that physically separates the cytoplasm of sister cells. As the final stage of cell division, abscission is poorly characterized during animal development. Here, we show that Aurora B and Survivin regulate the number of germ cells in each Drosophila egg chamber by inhibiting abscission during differentiation. This inhibition is mediated by an Aurora B-dependent phosphorylation of Cyclin B, as a phosphomimic form of Cyclin B rescues premature abscission caused by a loss of function of Aurora B. We show that Cyclin B localizes at the cytokinesis bridge, where it promotes abscission. We propose that mutual inhibitions between Aurora B and Cyclin B regulate the duration of abscission and thereby the number of sister cells in each cyst. Finally, we show that inhibitions of Aurora B and Cyclin-dependent kinase 1 activity in vertebrate cells also have opposite effects on the timing of abscission, suggesting a possible conservation of these mechanisms.
胞质分离是细胞分裂的最后一步，将姐妹细胞的细胞质物理分离。作为细胞分裂的最后阶段，胞质分离在动物发育过程中特征描述较差。在这里，我们表明 Aurora B 和 Survivin 通过在分化过程中抑制胞质分离来调节每个果蝇卵室中的生殖细胞数量。这种抑制是通过 Aurora B 依赖性的细胞周期蛋白 B 的磷酸化介导的，因为细胞周期蛋白 B 的磷酸模拟形式可以挽救由 Aurora B 功能丧失引起的过早胞质分离。我们表明细胞周期蛋白 B 定位于胞质分离桥，在那里它促进胞质分离。我们提出，Aurora B 和细胞周期蛋白 B 之间的相互抑制调节胞质分离的持续时间，从而调节每个小泡中姐妹细胞的数量。最后，我们表明脊椎动物细胞中 Aurora B 和细胞周期蛋白依赖性激酶 1 活性的抑制也对胞质分离的时间有相反的影响，这表明这些机制可能具有保守性。
