Full-Length Genomic Analysis of Korean Porcine Sapelovirus Strains

Abstract

Porcine sapelovirus (PSV), a species of the genus Sapelovirus within the family Picornaviridae, is associated with diarrhea, pneumonia, severe neurological disorders, and reproductive failure in pigs. However, the structural features of the complete PSV genome remain largely unknown. To analyze the structural features of PSV genomes, the full-length nucleotide sequences of three Korean PSV strains were determined and analyzed using bioinformatic techniques in comparison with other known PSV strains. The Korean PSV genomes ranged from 7,542 to 7,566 nucleotides excluding the 3′ poly(A) tail, and showed the typical picornavirus genome organization; 5′untranslated region (UTR)-L-VP4-VP2-VP3-VP1-2A-2B-2C-3A-3B-3C-3D-3′UTR. Three distinct cis-active RNA elements, the internal ribosome entry site (IRES) in the 5′UTR, a cis-replication element (CRE) in the 2C coding region and 3′UTR were identified and their structures were predicted. Interestingly, the structural features of the CRE and 3′UTR were different between PSV strains. The availability of these first complete genome sequences for PSV strains will facilitate future investigations of the molecular pathogenesis and evolutionary characteristics of PSV.

Pathogenesis of Korean Sapelovirus A in piglets and chicks

“…Contrary to our data, a recent study has reported that neuroinvasive English SV-A strain replication in the spinal cord could lead to severe adaptive immune responses (non-suppurative polioencephalomyelitis) without causing lesions in other tissues (Schock et al , 2014). This English SV-A strain (G5) is phylogenetically closer to the English V13 strain than to other SV-A strains circulating recently in Korea and China (Schock et al , 2014; Son et al , 2014a). The molecular basis involved in the differences in virulence and tropism among SV-A strains remains unknown.…”

“…Viruses in this family can cause a wide range of diseases, including intestinal, respiratory, neurological, cardiac, hepatic, mucocutaneous and systemic diseases of various severities in both humans and animals (Racaniello, 2013). Since porcine enterovirus 8 (PEV-8), simian type 2 picornavirus and duck picornavirus TW90A have a unique genomic organization different from other picornavirus genera (Son et al , 2014a), the genus Sapelovirus is a newly assigned member of the Picornaviridae family (Adams et al , 2015). The Sapelovirus genus consists of three species: Sapelovirus A (SV-A) formerly known as porcine sapelovirus, Sapelovirus B formerly named as simian sapelovirus and Avian sapelovirus formerly known as duck picornavirus TW90A (Adams et al , 2015).…”

“…The genomes of SV-As and other members in the genus Sapelovirus have the typical picornavirus genome organization: 5'-UTR-L-VP4-VP2-VP3-VP1-2A-2B-2C-3A-3B-3C-3D-3'-UTR (Krumbholz et al , 2002; Oberste et al , 2002, 2003; Son et al , 2014a; Tseng & Tsai, 2007). However, there are significant structural differences in the SV-A genome, e.g.…”

“…However, there are significant structural differences in the SV-A genome, e.g. the cis -acting RNA element ( CRE ) in the 2c coding region and kissing domain in the 3'-UTR vary between recent Korean and Chinese strains and older English and Chinese strains (Son et al , 2014a). These differences in antigenic diversity and structural features can influence the pathogenicity and/or host range restriction of SV-A strains, yet we have a limited understanding of the pathogenesis of SV-A (Son et al , 2014a).…”

Initiation of protein-primed picornavirus RNA synthesis

“…These structures are similar in the different genera of Picornaviridae although the location of these elements varies and overall their nucleotide sequences are highly divergent (Figs. 4A, 4B): cre s of PV and CVB3 ( Enterovirus ) in 2C ATPase (55, 164); cre s of HRV14, HRV3 and HRV76 ( Enterovirus ) in VP1 (89, 90); cre s of HRV2, HRV1a, HRV16 ( Enterovirus ) (52, 89); cre of species C Rhinovirus ( Enterovirus ) in VP2 (30); cre of TMEV and Mengovirus ( Cardiovirus) in VP2 (83); cre of HAV ( Hepatovirus) in 3D pol (178); cre of HPeV (Parechovirus) in VP0 (2); cre of Porcine Sapelovirus ( Sapelovirus ) in 2C ATPase (142). The only known exception is FMDV ( Aphthovirus ) whose cre is located in the 5’NTR rather than the coding sequences (88).…”