Costa Judite, Fu Chuanhai, Khare V Mohini, Tran Phong T
Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104 Institut Curie-Centre National de la Recherche Scientifique, UMR 144, Paris 75005 France.
Department of Biochemistry, University of Hong Kong, Pokfulam, Hong Kong.
Mol Biol Cell. 2014 Dec 1;25(24):3900-8. doi: 10.1091/mbc.E14-09-1370. Epub 2014 Sep 24.
Proper chromosome segregation is of paramount importance for proper genetic inheritance. Defects in chromosome segregation can lead to aneuploidy, which is a hallmark of cancer cells. Eukaryotic chromosome segregation is accomplished by the bipolar spindle. Additional mechanisms, such as the spindle assembly checkpoint and centromere positioning, further help to ensure complete segregation fidelity. Here we present the fission yeast csi2+. csi2p localizes to the spindle poles, where it regulates mitotic microtubule dynamics, bipolar spindle formation, and subsequent chromosome segregation. csi2 deletion (csi2Δ) results in abnormally long mitotic microtubules, high rate of transient monopolar spindles, and subsequent high rate of chromosome segregation defects. Because csi2Δ has multiple phenotypes, it enables estimates of the relative contribution of the different mechanisms to the overall chromosome segregation process. Centromere positioning, microtubule dynamics, and bipolar spindle formation can all contribute to chromosome segregation. However, the major determinant of chromosome segregation defects in fission yeast may be microtubule dynamic defects.
正确的染色体分离对于正确的遗传继承至关重要。染色体分离缺陷可导致非整倍体，这是癌细胞的一个标志。真核生物的染色体分离是通过双极纺锤体完成的。其他机制，如纺锤体组装检查点和着丝粒定位，进一步有助于确保完全的分离保真度。在这里，我们介绍了裂殖酵母csi2+。csi2p定位于纺锤体极，在那里它调节有丝分裂微管动力学、双极纺锤体形成以及随后的染色体分离。csi2缺失（csi2Δ）导致有丝分裂微管异常长、短暂单极纺锤体发生率高，以及随后的染色体分离缺陷率高。由于csi2Δ具有多种表型，它能够估计不同机制对整体染色体分离过程的相对贡献。着丝粒定位、微管动力学和双极纺锤体形成都可能有助于染色体分离。然而，裂殖酵母中染色体分离缺陷的主要决定因素可能是微管动态缺陷。
