Comparative 3D Genome Architecture in Vertebrates (Hi-C)

Three-dimensional genome architecture influences the regulation of essential nuclear processes, such as gene transcription. However, how 3D genome architecture is affected by evolutionary forces within major lineages remains unclear. Here, we report a comprehensive comparison of 3D genomes, using high resolution Hi-C data in fibroblast cells of fish, chickens, and 10 mammalian species. This analysis shows a correlation between genome size and chromosome length that affects chromosomal territory (CT) organization in the upper hierarchy of genome architecture, whereas lower hierarchical features, including local transcriptional availability of DNA, are selected through vertebrate’s evolution. Further, conservation of topologically associating domains (TADs) appears strongly associated with the modularity of expression profiles across species. Additionally, LINE and SINE transposable elements likely contribute to heterochromatin and euchromatin organization, respectively, during the evolution of genome architecture. These findings can guide ongoing investigations of genome evolution by extending our understanding of the mechanisms shaping genome architecture.