TAD cliques shape the 4-dimensional genome during dual lineage terminal differentiation

How genomic information is selectively utilized to direct spatial and temporal gene expression patterns during differentiation remains to be elucidated but it is clear that regulated changes in higher-order genomic architecture plays a fundamental role. Specifically, long range interactions within and between chromosomes and the position of chromosome territories in the nucleus are controlled by TADs and LADs respectively, but the relationship between these genomic organizers remains poorly understood Overall design: We analyzed the large-scale spatial reorganization of chromatin by generating matched Hi-C and nuclear lamin-chromatin contact datasets throughout a dual adipose/neuronal induction of human primary adipose stem cells. We have mapped Hi-C (TADs) and lamin-associated domains (LADs) in multiple steps during adipose stem cell differentiation to characterize the spatial and temporal link between genomic architecture and gene expression. We identify a new level of 4D genomic organization involving a long-range clustering of individual TADs or TAD pairs into TAD cliques. LADs appear to regulate their formation. (ASCs). We unveil a lineage-specific dynamic assembly and disassembly of repressive cliques of linearly non-contiguous TADs, and a time course-coupled relationship between TAD clique size and lamina association. Our findings reveal a new level of developmental genome organization and provide an overview of large-scale changes in the 4D nucleome during lineage-specific differentiation.

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Paulsen J, Liyakat Ali TM, Nekrasov M, Delbarre E, Baudement MO, Kurscheid S, Tremethick D, Collas P