The Telomeric Repeats of HHV-6A Do Not Determine the Chromosome into Which the Virus Is Integrated.

Human herpes virus 6A (HHV-6A) is able to integrate into the telomeric and subtelomeric regions of human chromosomes representing chromosomally integrated HHV-6A (ciHHV-6A). The integration starts from the right direct repeat (DR R ) region. It has been shown experimentally that perfect telomeric repeats (pTMR) in the DR R region are required for the integration, while the absence of the imperfect telomeric repeats (impTMR) only slightly reduces the frequency of HHV-6 integration cases. The aim of this study was to determine whether telomeric repeats within DR R may define the chromosome into which the HHV-6A integrates. We analysed 66 HHV-6A genomes obtained from public databases. Insertion and deletion patterns of DR R regions were examined. We also compared TMR within the herpes virus DR R and human chromosome sequences retrieved from the Telomere-to-Telomere consortium. Our results show that telomeric repeats in DR R in circulating and ciHHV-6A have an affinity for all human chromosomes studied and thus do not define a chromosome for integration.