Molecular evolution of avian reovirus:

Abstract

Nucleotide sequences of the S-class genome segments of 17 field-isolates and vaccine strains of avian reovirus (ARV) isolated over a 23-year period from different hosts, pathotypes, and geographic locations were examined and analyzed to define phylogenetic profiles and evolutionary mechanism. The S1 genome segment showed noticeably higher divergence than the other S-class genes. The sigma C-encoding gene has evolved into six distinct lineages. In contrast, the other S-class genes showed less divergence than that of the sigma C-encoding gene and have evolved into two to three major distinct lineages, respectively. Comparative sequence analysis provided evidence indicating extensive sequence divergence between ARV and other orthoreoviruses. The evolutionary trees of each gene were distinct, suggesting that these genes evolve in an independent manner. Furthermore, variable topologies were the result of frequent genetic reassortment among multiple cocirculating lineages. Results showed genetic diversity correlated more closely with date of isolation and geographic sites than with host species and pathotypes. This is the first evidence demonstrating genetic variability among circulating ARVs through a combination of evolutionary mechanisms involving multiple cocirculating lineages and genetic reassortment. The evolutionary rates and patterns of base substitutions were examined. The evolutionary rate for the sigma C-encoding gene and sigma C protein was higher than for the other S-class genes and other family of viruses. With the exception of the sigma C-encoding gene, which nonsynonymous substitutions predominate over synonymous, the evolutionary process of the other S-class genes can be explained by the neutral theory of molecular evolution. Results revealed that synonymous substitutions predominate over nonsynonymous in the S-class genes, even though genetic diversity and substitution rates vary among the viruses.

The genomic constellation of a novel avian orthoreovirus strain associated with runting-stunting syndrome in broilers

“…Despite the limited sequence information, the analyses provided evidence that accumulation of point mutations and reassortment among cognate genome segments could have played a key role in the origin and evolution of strain AVS-B. This is in agreement with previous studies conducted on a subset of ARV genes [15][16][17][18][19][20][21] and is consistent with evolutionary strategies of the majority of other virus species within the Reoviridae family.…”

“…The availability of sequence information published over the past decade allowed analyses of the overall genetic architecture of ARV strains, molecular evolutionary and epidemiologic studies to be performed, and sensitive and specific molecular detection methods to be designed [15][16][17][18][19][20][21][22][23][24][25][26]. To the best of our knowledge, this study is the first to report the whole genome sequence of a wild type chicken ARV associated with a disease condition other than tenosynovitis.…”

Characterization of the σC-encoding Gene from Musocvy Duck Reovirus

“…This result agreed with previous serological data that the DRV was antigenically different to chicken reovirus S1133 [10,18]. Comparison of the S14 rC protein sequence with the r1 sequence of the mammalian reovirus strains revealed 14-16% identity, which was of the same order of magnitude as that between ARV and MRV [19,22]. Amino acid sequences and secondary structure prediction analysis showed the shorter size of DRV rC had a heptapeptide repeat and leucine zipper patterns in the Nterminal region which agreed with the recent investigations to ARV [13,[21][22][23] and MRV [24], concluded that DRV rC protein is functionally and structurally related to chicken and MRV homologous protein.…”

“…Comparison of the S14 rC protein sequence with the r1 sequence of the mammalian reovirus strains revealed 14-16% identity, which was of the same order of magnitude as that between ARV and MRV [19,22]. Amino acid sequences and secondary structure prediction analysis showed the shorter size of DRV rC had a heptapeptide repeat and leucine zipper patterns in the Nterminal region which agreed with the recent investigations to ARV [13,[21][22][23] and MRV [24], concluded that DRV rC protein is functionally and structurally related to chicken and MRV homologous protein. rC-encoding gene, by virtue of its type-specific epitopes [14,24,27], might have been subjected to an initial increased rate of evolution under strong immunological selection.…”

Cell Entry of Avian Reovirus Follows a Caveolin-1-mediated and Dynamin-2-dependent Endocytic Pathway That Requires Activation of p38 Mitogen-activated Protein Kinase (MAPK) and Src Signaling Pathways as Well as Microtubules and Small GTPase Rab5 Protein

“…For the past several years, our laboratory has been studying molecular evolution of ARV and signaling pathways triggered by ARV required for apoptosis induction, virus replication, and cell cycle perturbations (22,(27)(28)(29)(30)(31)(32)(33). To date, the molecular events leading to endocytosis by ARV are still completely unknown.…”