Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer).
Chromosomes are cellular structures that contain the genetic material. A chromosome is comprised of a single DNA molecule that may be either circular or linear. The full complement of a cells chromosomes is called the genome.
The spindle assembly checkpoint ensures correct chromosome segregation and relies on kinetochore localization of the Bub1 and Mad1/Mad2 checkpoint proteins. Here the authors show that main function of Bub1 is to position Mad1 close to KNL1 MELT repeats in human cells.
Centromere maintenance depends on the persistence of the histone variant CENP-A at the centromeres. Here, the authors characterize the core centromeric nucleosome complex wherein CENP-C confers a stable CENP-A nucleosome conformation and CENP-N fastens CENP-A to the DNA.
Precise chromosome segregation during mitosis requires coordination of stable chromosome bi-orientation with anaphase onset, however the underlying mechanism is not clear. Here the authors show that inner centromere localization of the chromosomal passenger complex maintains centromeric cohesion on bi-oriented chromosomes and allows mitotic checkpoint silencing.
Sister chromatid cohesion during meiosis II (MII), maintained by securin-mediated inhibition of separase, is reduced in aged mouse oocytes. Here the authors show that, in MII oocytes, securin levels are reduced by increased destruction by the anaphase promoting complex/cyclosome.
Three-dimensional genome organization can shape gene expression by facilitating interactions between regulatory elements. The authors review the process of X-chromosome inactivation with a focus on chromatin organization and subnuclear localization of the active and inactive X chromosomes, as well as the potential roles of long non-coding RNAs.
One of the striking features of cells seen through a microscope is the heterogeneous organization of the nuclei. A combination of molecular methods and computational modeling has now been used to reconstruct accurate 3D structures of the genome inside single nuclei.
Micronucleation of missegregated chromatin can lead to substantial chromosome rearrangements via chromothripsis. However, the molecular details of micronucleus-based chromothripsis are still unclear. Now, an elegant system that specifically induces missegregation of the Y chromosome provides insight into this process, including a role for non-homologous end joining.
Although oxidative stress has long been considered to be a major factor contributing to telomere shortening, recent work has established that oxidative stress and DNA damage are linked to telomere lengthening. Now, Opresko and colleagues resolve this apparent discrepancy by showing that differential modulation of telomerase activity depends on the origin of a common oxidative guanine lesion.