Two novel bornaviruses identified in colubrid and viperid snakes

Florian Pfaff,Dennis Rubbenstroth

doi:10.1007/s00705-021-05138-3

Florian Pfaff, Dennis Rubbenstroth

Open Access

https://doi.org/10.1007/s00705-021-05138-3

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Abstract

We present the complete genome sequences of Caribbean watersnake bornavirus (CWBV) and Mexican black-tailed rattlesnake bornavirus (MRBV), which we identified in archived raw transcriptomic read data of a Caribbean watersnake (Tretanorhinus variabilis) and a Mexican black-tailed rattlesnake (Crotalus molossus nigrescens), respectively. The genomes of CWBV and MRBV have a length of about 8,900 nucleotides and comprise the complete coding regions and the untranslated regions. The overall genomic makeup and predicted gene content is typical for members of the genus Orthobornavirus within the family Bornaviridae. Alternative splicing was detected for the L and M genes. Based on a phylogenetic analysis of all viral proteins, we consider both viruses to be members of a single novel species within the genus Orthobornavirus. Both viruses form a distinct outgroup to all currently known orthobornaviruses. Based on the novel virus genomes, we furthermore identified closely related endogenous bornavirus-like nucleoprotein sequences in transcriptomic data of veiled chameleons (Chamaeleo calyptratus) and a common lancehead (Bothrops atrox).

Highlights

The family Bornaviridae belongs to the order Mononegavirales [1] and comprises viruses with a monopartite singlestranded RNA(-) genome that form enveloped and spherical virions with a diameter of 70-130 nm
The organization of the respective open reading frames varies among the different bornaviruses, and additional protein isotypes produced by alternative splicing [2] or start codon skipping [3] have been reported
Bornaviruses are divided into the three taxonomic genera: Orthobornavirus, Carbovirus, and Cultervirus [1, 4]

Summary

Introduction

The family Bornaviridae belongs to the order Mononegavirales [1] and comprises viruses with a monopartite singlestranded RNA(-) genome that form enveloped and spherical virions with a diameter of 70-130 nm. The organization of the respective open reading frames varies among the different bornaviruses, and additional protein isotypes produced by alternative splicing [2] or start codon skipping [3] have been reported. Partial sequences of exogenous orthobornavirus-like N, X, and P genes identified in a Gaboon viper (Bitis gabonica (Duméril, Bibron & Duméril, 1854)) [11] suggested a wider distribution of orthobornaviruses among snakes.

Results

Conclusion