Highly Divergent Genetic Variants of Soricid-Borne Altai Virus (Hantaviridae) in Eurasia Suggest Ancient Host-Switching Events.

Kang Kang,Cook Cook,Yashina Yashina,Yanagihara Yanagihara,Gu Gu

doi:10.3390/v11090857

Abstract

With the recent discovery of genetically distinct hantaviruses (family Hantaviridae) in shrews (order Eulipotyphla, family Soricidae), the once-conventional view that rodents (order Rodentia) served as the primordial reservoir hosts now appears improbable. The newly identified soricid-borne hantaviruses generally demonstrate well-resolved lineages organized according to host taxa and geographic origin. However, beginning in 2007, we detected sequences that did not conform to the prototypic hantaviruses associated with their soricid host species and/or geographic locations. That is, Eurasian common shrews (Sorex araneus), captured in Hungary and Russia, were found to harbor hantaviruses belonging to two separate and highly divergent lineages. We have since accumulated additional examples of these highly distinctive hantavirus sequences in the Laxmann’s shrew (Sorex caecutiens), flat-skulled shrew (Sorex roboratus) and Eurasian least shrew (Sorex minutissimus), captured at the same time and in the same location in the Sakha Republic in Far Eastern Russia. Pair-wise alignment and phylogenetic analysis of partial and full-length S-, M- and/or L-segment sequences indicate that a distinct hantavirus species related to Altai virus (ALTV), first reported in a Eurasian common shrew from Western Siberia, was being maintained in these closely related syntopic soricine shrew species. These findings suggest that genetic variants of ALTV might have resulted from ancient host-switching events with subsequent diversification within the Soricini tribe in Eurasia.

Highlights

Thottapalayam virus (TPMV), a previously unclassified virus isolated from an Asian house shrew (Suncus murinus), captured in southern India in 1964 [1], predated the discovery of Hantaan virus (HTNV), the prototype virus of hemorrhagic fever with renal syndrome (HFRS), in the striped field mouse (Apodemus agrarius) in Korea by more than a decade [2]
Among the shrew species in which HFRS antigens were originally detected more than 30 years ago, confirmation by reverse transcription polymerase chain reaction (RT-PCR) detection of hantavirus RNA was first achieved in the Eurasian common shrew [12]
In including expanded sequences of Altai virus (ALTV) and previously unreported ALTV-like hantavirus sequences from two Eurasian common shrews from Hungary and one Eurasian pygmy shrew from Poland, as well as the recently reported full-length genome of Lena River virus (LENV) strain Khekhtsir-Sc67 from a Laxmann’s shrew (Sorex caecutiens) in Far Eastern Russia [30], we demonstrate that this presumptive soricid-borne hantavirus species might represent an ancestral lineage that subsequently diversified within the Soricini tribe in Eurasia

Summary

Introduction

Thottapalayam virus (TPMV), a previously unclassified virus isolated from an Asian house shrew (Suncus murinus), captured in southern India in 1964 [1], predated the discovery of Hantaan virus (HTNV), the prototype virus of hemorrhagic fever with renal syndrome (HFRS), in the striped field mouse (Apodemus agrarius) in Korea by more than a decade [2] This observation went largely unnoticed and the subsequent detection of HFRS antigens in tissues of the Eurasian common shrew (Sorex araneus) and Eurasian water shrew (Neomys fodiens) in European Russia and the former Yugoslavia [3,4,5] failed to incite systematic exploration into the role of shrews in the evolutionary origins of hantaviruses. As evidence of spill-over events, SWSV has been detected in the Eurasian pygmy shrew (Sorex minutus) [17,22,26], Mediterranean water shrew (Neomys anomalus) ([26], GenBank EU418604), Siberian large-toothed shrew (Sorex daphaenodon) [27]

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