Li CX, Shi M, Tian JH, Lin XD, Kang YJ, Chen LJ, Qin XC, Xu J, Holmes EC, Zhang YZ. Unprecedented genomic diversity of RNA viruses in arthropods reveals the ancestry of negative-sense RNA viruses.
eLife 2015;
4. [PMID:
25633976 PMCID:
PMC4384744 DOI:
10.7554/elife.05378]
[Citation(s) in RCA: 527] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/27/2015] [Indexed: 12/12/2022] Open
Abstract
Although arthropods are important viral vectors, the biodiversity of arthropod
viruses, as well as the role that arthropods have played in viral origins and
evolution, is unclear. Through RNA sequencing of 70 arthropod species we discovered
112 novel viruses that appear to be ancestral to much of the documented genetic
diversity of negative-sense RNA viruses, a number of which are also present as
endogenous genomic copies. With this greatly enriched diversity we revealed that
arthropods contain viruses that fall basal to major virus groups, including the
vertebrate-specific arenaviruses, filoviruses, hantaviruses, influenza viruses,
lyssaviruses, and paramyxoviruses. We similarly documented a remarkable diversity of
genome structures in arthropod viruses, including a putative circular form, that
sheds new light on the evolution of genome organization. Hence, arthropods are a
major reservoir of viral genetic diversity and have likely been central to viral
evolution.
DOI:http://dx.doi.org/10.7554/eLife.05378.001
Many illnesses, including influenza, hemorrhagic fever, and rabies, are caused by a
group of viruses called negative-sense RNA viruses. The genetic information—or
genome—of these viruses is encoded in strands of RNA that must be copied
before they can be translated into the proteins needed to build new viruses. It is
currently known that there are at least eight different families of these viruses,
which have a wide range of shapes and sizes and arrange their RNA in different
ways.
Insects, spiders, and other arthropods carry many different RNA viruses. Many of
these viruses have not previously been studied, and those that have been studied so
far are mainly those that cause diseases in humans and other vertebrates. Researchers
therefore only know a limited amount about the diversity of the negative-sense RNA
viruses that arthropods harbor and how these viruses evolved. Studying how viruses
evolve helps scientists to understand what makes some viruses deadly and others
harmless and can also help develop treatments or vaccines for the diseases caused by
the viruses.
Li, Shi, Tian, Lin, Kang et al. collected 70 species of insects, spiders, centipedes,
and other arthropods in China and sequenced all the negative-sense RNA viruses in the
creatures. This revealed an enormous number of negative-sense RNA viruses, including
112 new viruses. Many of the newly discovered arthropod viruses appear to be the
ancestors of disease-causing viruses, including influenza viruses and the
filoviruses—the group that includes the Ebola virus. Indeed, it appears that
arthropods host many—if not all—of the negative-sense RNA viruses that
cause disease in vertebrates and plants.
While documenting the new RNA viruses and how they are related to each other, Li et
al. found many different genome structures. Some genomes were segmented, which may
play an important role in evolution as segments can be easily swapped to create new
genetic combinations. Non-segmented and circular genomes were also found. This
genetic diversity suggests that arthropods are likely to have played a key role in
the evolution of new viruses by acting as a site where many different viruses can
interact and exchange genetic information.
DOI:http://dx.doi.org/10.7554/eLife.05378.002
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