LBCMCP, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse, France.
CNRS, INSERM, Aix Marseille Univ, Institut Paoli-Calmettes, CRCM, 13273 Marseille, France.
Mol Biol Cell. 2020 Apr 15;31(9):889-905. doi: 10.1091/mbc.E20-01-0021. Epub 2020 Feb 26.
In mitosis, while the importance of kinetochore (KT)-microtubule (MT) attachment has been known for many years, increasing evidence suggests that telomere dysfunctions also perturb chromosome segregation by contributing to the formation of chromatin bridges at anaphase. Recent evidence suggests that Aurora B kinase ensures proper chromosome segregation during mitosis not only by controlling KT-MT attachment but also by regulating telomere and chromosome arm separation. However, whether and how Aurora B governs telomere separation during meiosis has remained unknown. Here, we show that fission yeast Aurora B localizes at telomeres during meiosis I and promotes telomere separation independently of the meiotic cohesin Rec8. In meiosis II, Aurora B controls KT-MT attachment but appears dispensable for telomere and chromosome arm separation. Likewise, condensin activity is nonessential in meiosis II for telomere and chromosome arm separation. Thus, in meiosis, the requirements for Aurora B are distinct at centromeres and telomeres, illustrating the critical differences in the control of chromosome segregation between mitosis and meiosis II.
在有丝分裂过程中,尽管动粒(KT)-微管(MT)附着的重要性已经众所周知多年,但越来越多的证据表明,端粒功能障碍也通过在后期形成染色质桥来干扰染色体分离。最近的证据表明,Aurora B 激酶不仅通过控制 KT-MT 附着,还通过调节端粒和染色体臂分离,来确保有丝分裂过程中染色体的正确分离。然而,Aurora B 是否以及如何在减数分裂过程中控制端粒分离仍然未知。在这里,我们发现裂殖酵母 Aurora B 在减数分裂 I 期间定位于端粒,并独立于减数分裂黏合蛋白 Rec8 促进端粒分离。在减数分裂 II 中,Aurora B 控制 KT-MT 附着,但对于端粒和染色体臂分离似乎是可有可无的。同样,在减数分裂 II 中,凝聚素活性对于端粒和染色体臂分离不是必需的。因此,在减数分裂过程中,Aurora B 在着丝粒和端粒处的需求是不同的,这说明了有丝分裂和减数分裂 II 中染色体分离控制的关键差异。