Genome reorganisation and expansion shape 3D genome architecture and define a distinct regulatory landscape in coleoid cephalopods.

Large-scale chromosomal rearrangements and repeat expansions in coleoid cephalopods are linked to species-specific chromatin loops and regulatory patterns.

• Why it matters: Understanding how genomic changes influence organismal innovations is challenging due to complex genome architecture and long evolutionary timescales, especially in highly modified species like coleoids.
• What they did: The study used Micro-C, RNA-seq, and ATAC-seq across multiple coleoid species, developmental stages, and tissues, identifying conserved chromatin domains and hundreds of species- and context-specific chromatin loops.
• The result: Findings suggest that differential evolutionary constraints on 3D genome topology enable the emergence of novel regulatory interactions, supporting the evolution of complex traits in coleoids.