Genetic Characterization of a Recombinant Myxoma Virus in the Iberian Hare (Lepus granatensis).

Ana Águeda-Pinto,Pedro J Esteves,Arvind Varsani,Simona Kraberger,Mário Abrantes,Grant Mcfadden,Christian Gortázar,Maria A Risalde,Ana Lemos De Matos

doi:10.3390/v11060530

Abstract

Myxomatosis is a lethal disease in wild European and domestic rabbits (Oryctolagus cuniculus), which is caused by a Myxoma virus (MYXV) infection—a leporipoxvirus that is found naturally in some Sylvilagus rabbit species in South America and California. The introduction of MYXV into feral European rabbit populations of Australia and Europe, in the early 1950s, demonstrated the best-documented field example of host–virus coevolution, following a cross-species transmission. Recently, a new cross-species jump of MYXV has been suggested in both Great Britain and Spain, where European brown hares (Lepus europaeus) and Iberian hares (Lepus granatensis) were found dead with lesions consistent with those observed in myxomatosis. To investigate the possibility of a new cross-species transmission event by MYXV, tissue samples collected from a wild Iberian hare found dead in Spain (Toledo region) were analyzed and deep sequenced. Our results reported a new MYXV isolate (MYXV Toledo) in the tissues of this species. The genome of this new virus was found to encode three disruptive genes (M009L, M036L, and M152R) and a novel ~2.8 kb recombinant region, which resulted from an insertion of four novel poxviral genes towards the 3’ end of the negative strand of its genome. From the open reading frames inserted into the MYXV Toledo virus, a new orthologue of a poxvirus host range gene family member was identified, which was related to the MYXV gene M064R. Overall, we confirmed the identity of a new MYXV isolate in Iberian hares, which, we hypothesized, was able to more effectively counteract the host defenses in hares and start an infectious process in this new host.

Highlights

Myxoma virus (MYXV), a poxvirus belonging to the Leporipoxvirus genus, is the etiological agent of myxomatosis, which is a highly lethal viral disease in wild and domestic European rabbits (Oryctolagus cuniculus) [1]
We reported that the new recombinant insertion region of MYXV-Tol only contained one predicted host range protein (Figures 2 and 3), which reinforced our hypothesis that this new gene insertion region found at the left end of the MYXV-Tol genome was probably not a result of a recombinant event between two leporipoxviruses, Viruses
Other thanRemarks the disruption of M009L, M036L, and M152R, the MYXV-Tol was found to have a full complement of disruption genes present in other

Summary

Introduction

Myxoma virus (MYXV), a poxvirus belonging to the Leporipoxvirus genus, is the etiological agent of myxomatosis, which is a highly lethal viral disease in wild and domestic European rabbits (Oryctolagus cuniculus) [1]. The virus has its natural host in the South American tapeti, or forest rabbit (Sylvilagus brasiliensis), where it causes an innocuous and localized cutaneous fibroma, at the inoculation site [2]. Californian MYXV strains, for which the natural host is Sylvilagus bachmani (brush rabbit), and the rabbit fibroma virus (RFV) found in Sylvilagus floridanus (eastern cottontail) [2,4]. The MYXV does not seem to cause significant clinical diseases in the natural Sylvilagus hosts, though being highly pathogenic to the naive Oryctolagus host makes it a classic example of a pathogen that is highly virulent in a new host species with no evolutionary history of adaptation to that pathogen

Methods

Results

Conclusion