Centromeres are scaffolds for the assembly of kinetochores that ensure chromosome segregation during cell division. How vertebrate centromeres obtain a three-dimensional structure to accomplish their primary function is unclear. Using super-resolution imaging, capture-C, and polymer modeling, we show that vertebrate centromeres are partitioned by condensins into two subdomains during mitosis. The bipartite structure is found in human, mouse, and chicken cells and is therefore a fundamental feature of vertebrate centromeres. Super-resolution imaging and electron tomography reveal that bipartite centromeres assemble bipartite kinetochores, with each subdomain binding a distinct microtubule bundle. Cohesin links the centromere subdomains, limiting their separation in response to spindle forces and avoiding merotelic kinetochore-spindle attachments. Lagging chromosomes during cancer cell divisions frequently have merotelic attachments in which the centromere subdomains are separated and bioriented. Our work reveals a fundamental aspect of vertebrate centromere biology with implications for understanding the mechanisms that guarantee faithful chromosome segregation.

着丝粒是着丝粒组装的支架，确保细胞分裂过程中染色体分离。脊椎动物着丝粒如何获得三维结构来完成其主要功能尚不清楚。使用超分辨率成像、捕获-C 和聚合物建模，我们表明脊椎动物着丝粒在有丝分裂过程中被凝缩蛋白分成两个子域。这种二分结构存在于人类、小鼠和鸡细胞中，因此是脊椎动物着丝粒的基本特征。超分辨率成像和电子断层扫描显示，二分着丝粒组装二分动粒，每个子域结合不同的微管束。粘连蛋白连接着丝粒子域，限制它们响应纺锤体力而分离，并避免动粒-纺锤体附着。癌细胞分裂过程中的滞后染色体经常具有粒粒附着，其中着丝粒子域是分离的和双向的。我们的工作揭示了脊椎动物着丝粒生物学的一个基本方面，对于理解保证染色体忠实分离的机制具有重要意义。