Chromosomes articles from across Nature Portfolio

When transcription by RNA polymerase II is stalled by ultraviolet-induced DNA damage, it recruits repair factors, leading to excision of the damaged site and DNA synthesis to fill the gap. Three new studies show that, for aldehyde-induced DNA crosslinks, repair is activated by the same factors, but without base excision and gap filling.

Whether bacterial replisome progression follows a “factory” or “track” model remains a long-standing controversy. Here, the authors find that cells can switch between the two models, in a process governed by dynamic chromosome organization processes.

Meiotic cells deliberately break their DNA to allow chromosomes to swap genetic material. Here, authors reveal genetically separable pathways controlling the seeding and growth of chromosome-bound protein condensates responsible for DNA breaks.

A comparison of two complete sets of human centromeres reveals that the centromeres show at least a 4.1-fold increase in single-nucleotide variation compared with their unique flanks, and up to 3-fold variation in size, resulting from an accelerated mutation rate.

Here the authors show that PARP2 drives telomere fragility by orchestrating the Break-induced replication (BIR) pathway. This promotes DNA end resection and DNA synthesis via the regulation of POLD3.

When transcription by RNA polymerase II is stalled by ultraviolet-induced DNA damage, it recruits repair factors, leading to excision of the damaged site and DNA synthesis to fill the gap. Three new studies show that, for aldehyde-induced DNA crosslinks, repair is activated by the same factors, but without base excision and gap filling.

Marnie Blewitt highlights the visionary 1961 paper by Mary Lyon in which she proposed that dosage compensation in female mammals involves X-inactivation and recognized its implications for sex-specific phenotypes in X-linked disorders.

New work shows that in mammals, the iDDR motif of telomere factor TRF2 inhibits the MRE11–RAD50–NBS1 (MRN) complex at chromosome ends through a direct iDDR–RAD50 interaction. Unrelated protein motifs in yeasts inhibit MRN functions via an analogous mechanism, suggesting a convergent evolution in eukaryotes to control MRN action at telomeres.

By studying the folding of chromosomes relative to nuclear bodies in single-cell models, we reveal specialized subnuclear microenvironments linked to specific gene functions. Our models provide insights into a variety of structural features of the genome and unveil key structure–function correlations.

Inactivation of one of the two female X chromosomes involves condensing it into a repressive subnuclear territory, which is depleted of transcriptional components and undergoes late-stage DNA replication. Two new studies unravel how compartmentalization of the inactive mammalian X chromosome affects transcription and DNA replication.