The extraordinary evolutionary history of the reticuloendotheliosis viruses

Niewiadomska, A.M. and Gifford, R.J. (2013) The extraordinary evolutionary history of the reticuloendotheliosis viruses. PLoS Biology, 11(8), e1001642. (doi: 10.1371/journal.pbio.1001642)

Abstract

The reticuloendotheliosis viruses (REVs) comprise several closely related amphotropic retroviruses isolated from birds. These viruses exhibit several highly unusual characteristics that have not so far been adequately explained, including their extremely close relationship to mammalian retroviruses, and their presence as endogenous sequences within the genomes of certain large DNA viruses. We present evidence for an iatrogenic origin of REVs that accounts for these phenomena. Firstly, we identify endogenous retroviral fossils in mammalian genomes that share a unique recombinant structure with REVs—unequivocally demonstrating that REVs derive directly from mammalian retroviruses. Secondly, through sequencing of archived REV isolates, we confirm that contaminated Plasmodium lophurae stocks have been the source of multiple REV outbreaks in experimentally infected birds. Finally, we show that both phylogenetic and historical evidence support a scenario wherein REVs originated as mammalian retroviruses that were accidentally introduced into avian hosts in the late 1930s, during experimental studies of P. lophurae, and subsequently integrated into the fowlpox virus (FWPV) and gallid herpesvirus type 2 (GHV-2) genomes, generating recombinant DNA viruses that now circulate in wild birds and poultry. Our findings provide a novel perspective on the origin and evolution of REV, and indicate that horizontal gene transfer between virus families can expand the impact of iatrogenic transmission events.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gifford, Dr Robert
• Authors: Niewiadomska, A.M., and Gifford, R.J.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Virus Research
• Journal Name: PLoS Biology
• Publisher: Public Library of Science
• ISSN: 1544-9173
• ISSN (Online): 1545-7885
• Copyright Holders: Copyright © 2013 The Authors
• First Published: First Published in PLoS Biology 11(8):e1001642
• Publisher Policy: Reproduced under a Creative Commons License