All articles tagged with #genome architecture
Cohesin loop extrusion accumulates at stalled replication forks to reshape nascent DNA contacts, slowing fork progression and promoting fork reversal under replication stress; this NIPBL-dependent mechanism also tightens inter- and intra-replicon contacts to preserve genome stability, and its disruption sensitizes cells to genotoxic agents, with implications for cancers carrying cohesin mutations.
A single-cell study of the aging human hippocampus shows midlife immune shifts from embryonically derived microglia to inflammatory blood-like cells, loss of blood-brain barrier cells, and widespread remodeling of genome architecture across brain cell types, suggesting aging is an active, coordinated remodeling process linked to neurodegenerative risk and revealing potential therapeutic targets.
The article discusses how the 3D folding of DNA, specifically DNA looping, plays a crucial role in regulating transcription by bringing distant genetic elements into proximity, with experimental evidence showing that the repression effect oscillates with the insertion or deletion of DNA segments corresponding to the DNA helix's periodicity.
A study on Lepidoptera, the insect order comprising moths and butterflies, reveals the dynamics of chromosome evolution and karyotype variation. The research, based on 210 chromosomal genome assemblies, identifies ancestral linkage groups (ALGs) and shows that most species have retained intact ALGs, with infrequent fusions and rare fissions. However, eight lineages have experienced extensive chromosomal rearrangements, resulting in fragmented Merian elements. The study provides insights into the constraints and mechanisms influencing chromosome evolution in Lepidoptera.