Global changes in the nuclear positioning of chromatin domains and genomic interactions that orchestrate B cell fate

The genome is folded into domains that are located in either transcriptionally inert or permissive compartments. Here we used genome-wide strategies to characterize domains during B cell development. Structured Interaction Matrix Analysis revealed that CTCF occupancy was primarily associated with intra-domain interactions, whereas p300, E2A, Pax5 and PU.1 were involved with intra- and inter-domain interactions that are developmentally regulated. We identified a spectrum of genes that switched nuclear location during early B cell development. In progenitors the transcriptionally inactive Ebf1 locus was sequestered at the nuclear lamina, thereby preserving multipotency, however upon development into the pro-B cell stage Ebf1 and other genes switched compartments to establish de novo intra- and inter-domain interactions that were associated with B lineage specific transcription signatures. Performed Hi-C, GRO-seq, and ChIP-seq to pinpoint the underlying molecular mechanisms that link transcriptional regulation to genomic structure and architecture in lymphocyte development