genomeorganisationen

Genome organisation refers to the spatial and structural arrangement of genetic material within cells and how this arrangement shapes gene regulation, replication, and genome stability. It includes DNA packaging, chromatin state, chromosome positioning, and three-dimensional contacts that bring distant elements into proximity.

In prokaryotes, genomes are typically a single circular chromosome with plasmids. They are organized in a nucleoid, compacted by nucleoid-associated proteins and DNA supercoiling, enabling efficient replication and transcription with limited higher-order folding.

In eukaryotes, DNA wraps around histones to form chromatin and is organized into chromosomes that occupy distinct nuclear territories. Higher-order structures include compartments A and B, loops, and topologically associating domains (TADs). Cohesin and CTCF help shape these contacts, influencing enhancer–promoter interactions, replication timing, and recombination. Epigenetic marks and lamina interactions further modulate activity.

Genome organisation has functional consequences: it affects when and where genes are expressed, how the genome is replicated, and how it responds to damage. It changes during development and differentiation and can be altered in disease, particularly cancer, where rearrangements can disrupt regulatory networks.

Studying genome organisation employs chromosome conformation capture techniques (3C, Hi-C) and imaging approaches to map three-dimensional contacts and nuclear architecture. Together, these tools help link spatial genome features to transcription, replication, and genome stability.