The Deltaretrovirus genus of retroviruses (family Retroviridae) includes the human T cell leukemia viruses and bovine leukemia virus (BLV). Relatively little is known about the biology and evolution of these viruses, because only a few species have been identified and the genomic 'fossil record' is relatively sparse. Here, we report the discovery of multiple novel endogenous retroviruses (ERVs) derived from ancestral deltaretroviruses. These sequences-two of which contain complete or near complete internal coding regions-reside in genomes of several distinct mammalian orders, including bats, carnivores, cetaceans, and insectivores. We demonstrate that two of these ERVs contain unambiguous homologs of the tax gene, indicating that complex gene regulation has ancient origins within the Deltaretrovirus genus. ERVs demonstrate that the host range of the deltaretrovirus genus is much more extensive than suggested by the relatively small number of exogenous deltaretroviruses described so far, and allow the evolutionary timeline of deltaretrovirus-mammal interaction to be more accurately calibrated.

• Keywords
• BLV, Deltaretrovirus, Endogenous retrovirus, Evolution, HTLV, Leukemia, PTLV, Paleovirology, Retrovirus,
• MeSH
• Deltaretrovirus genetics   MeSH
• Endogenous Retroviruses genetics   isolation & purification   MeSH
• Phylogeny MeSH
• Genome, Viral MeSH
• Genes, pX MeSH
• Host Specificity * MeSH
• Humans MeSH
• Evolution, Molecular * MeSH
• Paleontology MeSH
• Mammals virology   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

It has now been more than two years since we said our last goodbye to Jan Svoboda (14 [...].

• MeSH
• Humans MeSH
• Retroviridae classification   genetics   isolation & purification   physiology   MeSH
• Retroviridae Infections virology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH
• Introductory Journal Article MeSH
• Editorial MeSH

Endogenous retrovirus (ERV) sequences provide a rich source of information about the long-term interactions between retroviruses and their hosts. However, most ERVs are derived from a subset of retrovirus groups, while ERVs derived from certain other groups remain extremely rare. In particular, only a single ERV sequence has been identified that shows evidence of being related to an ancient Deltaretrovirus, despite the large number of vertebrate genome sequences now available. In this report, we identify a second example of an ERV sequence putatively derived from a past deltaretroviral infection, in the genomes of several species of horseshoe bats (Rhinolophidae). This sequence represents a fragment of viral genome derived from a single integration. The time of the integration was estimated to be 11-19 million years ago. This finding, together with the previously identified endogenous Deltaretrovirus in long-fingered bats (Miniopteridae), suggest a close association of bats with ancient deltaretroviruses.

• Keywords
• Deltaretrovirus, bats, endogenous retrovirus, evolution, genomics, retrovirus,
• MeSH
• Chiroptera classification   virology   MeSH
• Deltaretrovirus classification   genetics   MeSH
• Endogenous Retroviruses classification   genetics   MeSH
• Phylogeny MeSH
• Genome genetics   MeSH
• Genomics MeSH
• Terminal Repeat Sequences genetics   MeSH
• Evolution, Molecular MeSH
• Recombination, Genetic MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH