Endogenous retroviruses (ERVs) constitute a significant part of vertebrate genomes. They originated from past retroviral infections and some of them retain transcriptional activity. The key mechanism avoiding uncontrolled ERV transcription is DNA methylation-mediated epigenetic silencing. Despite numerous studies describing the involvement of ERV activity in cellular processes, epigenetic regulation of ERVs is still poorly understood. We previously described a cervid endogenous retrovirus (CrERV) in the mule deer genome. This virus exhibits massive insertional polymorphism, suggesting recent activity. Here we employed NGS-based strategy to determine the methylation pattern of CrERV integrations in four mule deer. Besides the vast majority of methylated integrations, we identified a tiny fraction of demethylated proviral copies. These copies represent evolutionary older integrations located near gene promoters. In general, our work is a first attempt to characterize the epigenetic landscape of insertionally polymorphic ERV on a whole-genome scale and offers insight into its interactions with a host.

Institute of Molecular Genetics The Czech Academy of Sciences Videnska 1083 Prague 14220 Czech Republic

Institute of Molecular Genetics The Czech Academy of Sciences Videnska 1083 Prague 14220 Czech Republic; Faculty of Science Charles University Albertov 6 128 43 Praha 2 Czech Republic

Citace poskytuje Crossref.org

Long Terminal Repeats of Gammaretroviruses Retain Stable Expression after Integration Retargeting