Remnants of an Ancient Deltaretrovirus in the Genomes of Horseshoe Bats (Rhinolophidae).

Tomáš Hron,Daniel Elleder,Pavel Hulva,Tamás Görföl,Jan Pačes,Petr Benda,Robert Gifford,Helena Farkašová

doi:10.3390/v10040185

Abstract

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.

Highlights

Retroviruses have an unusual replication strategy in which a copy of the viral genome is integrated into the genome of the infected host cell
When retroviral infection occurs in a germline cell, integrated proviruses can potentially enter the germline of the host species, so that they are vertically inherited from one generation to the as host alleles called endogenous retroviruses (ERVs)
We detected a sequence in the genome of R. sinicus that disclosed similarity to MINERVa—a recently described endogenous Deltaretrovirus from the genome of Miniopterus bats [3]

Summary

Introduction

Retroviruses (family Retroviridae) have an unusual replication strategy in which a copy of the viral genome is integrated into the genome of the infected host cell. When retroviral infection occurs in a germline cell (i.e., sperm, eggs or early embryo), integrated proviruses can potentially enter the germline of the host species, so that they are vertically inherited from one generation to the as host alleles called endogenous retroviruses (ERVs). These sequences are common in the genome of most vertebrates (especially mammals) and have exerted an important impact on the evolution of host genomes [1]. It is really only via the retrospective evidence of ERVs that we can be certain retroviruses have been infecting humans and other mammalian species for many millions of years

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Conclusion