SRA

Using chromatin conformation capture methods, we learned that the latent episome of the human Epstein-Barr virus (EBV) displays preferential chromosome association that correlates with gene density. The episome avoids gene-rich chromosomes and favors gene-poor chromosomes. Kaposi's sarcoma-associated herpesvirus behaves similarly, but human papillomavirus does not, suggesting limited evolutionary conservation of this strategy. Moreover, the strongest contacts we detected between the human genome and EBV episome localized to OriP, the latent origin of replication. This genetic element, and the EBNA1 protein that binds there, are sufficient to reconstitute chromosome association preferences of the entire episome. Upon reactivation from latency, however, these preferences are lost. Detailed mapping of changes in interchromosomal contacts reveal that the episome moves away from repressive heterochromatin and toward activating euchromatin. Our work adds three-dimensional relocalization to the molecular events that occur during the genetic switch from EBV latency to reactivation. The involvement of only a myriad of interchromosomal contacts also argues for a possible role of this type of long-range association in gene regulation. Overall design: Hi-C examination of host-viral genome interactions during reactivation and latency