Submitted to: Avian Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/15/2005
Publication Date: 3/10/2005
Citation: Sellers, H.S., Linnemann, E.G., Pereira, L., Kapczynski, D.R. 2005. Phylogenetic analysis of the sigma 2 protein gene of turkey reoviruses. Avian Diseases. 48:651-7. Interpretive Summary: Poult enteritis and mortality syndrome (PEMS) is a highly infectious disease of turkey poults. Efforts to identify the causative agent of PEMS have resulted in the identification of a novel turkey reovirus. We were the first to describe and compare the genetic relationship of the turkey reovirus associated with PEMS to other avian reoviruses. This report extends those findings by presenting sequence data from 4 additional turkey reoviruses collected from 1972-1999. Results indicate the turkey reoviruses are separate from other avian reoviruses and should be considered a distinct virus species.
Technical Abstract: The open reading frame of the S3 segment encoding the sigma 2 protein of four turkey reovirus field isolates was analyzed for sequence heterogeneity. The turkey reoviruses we present here have a 97% amino acid identity to turkey NC 98. The S3 nucleotide and amino acid sequence similarity was < 61% and 78-80 %, respectively when compared to the chicken reovirus isolates. Comparison of amino acid sequences, from chickens and turkeys with a duck isolate revealed a 53% and 55% similarity, respectively. Phylogenetic analyses, based on both nucleotide and amino acid sequence, resulted in three major groups among the avian reoviruses, clearly separated by species. The results of this study provide further evidence, based on the deduced sigma 2 sequence, that turkey reoviruses form a distinct, separate group relative to chicken and duck isolates. In addition, due to the limited sequence identity with their avian counterparts, turkey reoviruses could potentially be considered a separate virus species within subgroup 2 of the Orthoreovirus genus.