Identification and characterization of a new bocavirus species in gorillas

Abstract

A novel parvovirus, provisionally named Gorilla Bocavirus species 1 (GBoV1), was identified in four stool samples from Western gorillas (Gorilla gorilla) with acute enteritis. The complete genomic sequence of the new parvovirus revealed three open reading frames (ORFs) with an organization similar to that of known bocaviruses. Phylogenetic analysis using complete capsid and non structural (NS) gene sequence suggested that the new parvovirus is most closely related to human bocaviruses (HBoV). However, the NS ORF is more similar in length to the NS ORF found in canine minute virus and bovine parvovirus than in HBoV. Comparative genetic analysis using GBoV and HBoV genomes enabled characterization of unique splice donor and acceptor sites that appear to be highly conserved among all four HBoV species, and provided evidence for expression of two different NS proteins in all primate bocaviruses. GBoV is the first non-human primate bocavirus identified and provides new insights into the genetic diversity and evolution of this highly prevalent and recently discovered group of parvoviruses.

Figure 1. Phylogenetic analysis of GBoV1.

(A) Full length structural protein (VP1/2) sequences of all HBoV and animal bocavirus strains available in GenBank were used to determine phylogeny of GBoV1 by neighbor-joining analysis of pairwise distances between translated amino acid sequences. Bootstrap re-sampling was used to determine robustness of individual clades (values above 70% shown above the branches). (B) The 4 major open reading frames of GBoV1 were analyzed using maximum likelihood composition analysis method (MEGA4.1) comparing pairwise distances of translated sequences of representative variants (reference sequence) of all four HBoV species. Accession numbers of sequences used precedes the name of corresponding bocavirus species.

Figure 2. Genomic organization of primate bocaviruses.

(A) Shows genomic organization of known primate and animal bocavirus species. Small arrows indicate positions (numbers) of stop codons in NS gene of human bocaviruses. (B) Shows consensus eukaryotic RNA splicing sequence and presence of similar sequence motifs found conserved in NS genes of all primate bocaviruses. Numbers represent nucleotide positions on respective genomes; stop codons found in HBoV species are underlined in red. No stop codon was found in the NS1 gene region of GBoV1. (C) Shows presence of substantive protein identity between the extended NS protein of HBoVs and longer uninterrupted NS protein of GBoV1. Numbers represent relative amino acid positions of different bocavirus NS proteins.