We have reported a novel bovine rotavirus, the AzuK-1 (G21P [29]) strain, isolated from an asymptomatic calf. We isolated another bovine rotavirus, the Dai-10 strain, bearing new G24P [33] genotypes, assigned by the Rotavirus Classification Working Group (RCWG), from an asymptomatic cow in Hyogo Prefecture, Japan in 2007. To gain an insight into the origins and evolution of these strains, we determined the complete ORF sequences of all 11 genes of the two strains. The NSP3 genes of both strains were confirmed to belong to a new NSP3 genotype, T9, by the RCWG. Genotype determination of AzuK-1 and Dai-10 strains revealed that eight gene segments of both strains possessed genotypes typically observed in bovine rotaviruses, with the exception of VP4, VP7 and NSP3 gene segments. Unexpectedly, phylogenetic analyses showed that VP6 and NSP2 gene segments of the AzuK-1 and Dai-10 strains were clustered with those of simian or canine/feline rotaviruses, rather than with those of bovine rotaviruses. These findings indicate the possibility that both strains originated by interspecies transmission and multiple reassortment events involving bovine, simian and canine/feline rotaviruses, resulting in the introduction of some genes into the genetic background of bovine rotaviruses. INTRODUCTIONGroup A rotaviruses are the major pathogens causing acute gastroenteritis in infants and a wide range of animals, including birds. Rotavirus-induced diarrhoea is a serious public health problem worldwide, responsible for more than 600 000 child deaths each year (Parashar et al., 2006). Likewise, in domestic animals, rotavirus-induced diarrhoea is a major problem causing significant economic losses (Dhama et al., 2009;Martella et al., 2010).Rotaviruses are members of the family Reoviridae. Rotaviruses possess a genome of 11 segments of dsRNA, which encode six viral structural proteins (VP1-VP4, VP6 and VP7) and six non-structural proteins (NSP1-NSP6). Because of the segmented nature of the genome, a reassortment event can occur in cells co-infected with two or more different strains (Estes & Kapikian, 2007;Palombo, 2002;Ramig, 1997). The rotavirus virion is a triple-layered icosahedral particle. The outer capsid is composed of VP7 and VP4. They elicit neutralizing antibodies independently. In a dual classification system, rotaviruses are classified into 24 G genotypes and 32 P genotypes based on the nucleotide sequences of VP7 and VP4 genes, respectively (Collins et al., 2010; Esona et al., 2010;Matthijnssens et al., 2006Matthijnssens et al., , 2008a Schumann et al., 2009; Solberg et al., 2009;Ursu et al., 2009). Recently, a new classification system has been established using nucleotide sequences of all of the 11 genomic RNA segments by the Rotavirus Classification Working Group (RCWG) (Matthijnssens et al., 2008b). In this system, the The GenBank/EMBL/DDBJ accession numbers for the sequences reported in this paper are AB513836-AB513838 and AB573070-AB573086.Supplementary material is available with the online version of this paper. , 2...

These data represent direct evidence that P-protein-STAT interaction is critical to rabies, and provide novel insights into the mechanism by which RABV coordinates distinct functions in interferon antagonism and replication.

e Rabies virus (RABV), which is transmitted via a bite wound caused by a rabid animal, infects peripheral nerves and then spreads to the central nervous system (CNS) before causing severe neurological symptoms and death in the infected individual. Despite the importance of this ability of the virus to spread from a peripheral site to the CNS (neuroinvasiveness) in the pathogenesis of rabies, little is known about the mechanism underlying the neuroinvasiveness of RABV. In this study, to obtain insights into the mechanism, we conducted comparative analysis of two fixed RABV strains, Nishigahara and the derivative strain Ni-CE, which cause lethal and asymptomatic infections, respectively, in mice after intramuscular inoculation. Examination of a series of chimeric viruses harboring the respective genes from Nishigahara in the genetic background of Ni-CE revealed that the Nishigahara phosphoprotein (P) gene plays a major role in the neuroinvasiveness by mediating infection of peripheral nerves. The results obtained from both in vivo and in vitro experiments strongly suggested that the Nishigahara P gene, but not the Ni-CE P gene, is important for stable viral replication in muscle cells. Further investigation based on the previous finding that RABV phosphoprotein counteracts the host interferon (IFN) system demonstrated that the Nishigahara P gene, but not the Ni-CE P gene, functions to suppress expression of the beta interferon (IFN-␤) gene (Ifn-␤) and IFN-stimulated genes in muscle cells. In conclusion, we provide the first data strongly suggesting that RABV phosphoprotein assists viral replication in muscle cells by counteracting the host IFN system and, consequently, enhances infection of peripheral nerves. R abies virus (RABV), a member of the genus Lyssavirus of the family Rhabdoviridae, infects almost all kinds of mammals, including humans, and causes a severe neurological disease with a high mortality rate of about 100% after a long and inconstant incubation period (usually 20 to 90 days in humans) (reviewed in reference 1). It is estimated that more than 55,000 people die of rabies every year, mainly in Asia and Africa (2), due to the absence of an effective cure and also the complexity and expensiveness of current postexposure prophylaxis, which requires medical treatment (i.e., rabies vaccination) five times over a period of 28 days. In order to develop both therapeutic and novel prophylaxis approaches for rabies, it is necessary to fully understand the pathogenesis of rabies.The pathogenesis of rabies essentially relies on viral spread to and in the nervous system of the infected individual (reviewed in reference 1). RABV secreted into saliva of a rabid animal is generally transmitted via a bite wound caused by the infected animal. After transmission, RABV infects peripheral nerves and then spreads to the central nervous system (CNS) via retrograde axonal transport, followed by active viral replication and spread in the CNS, culminating in severe neurological symptoms and lethal outcome. To date, studies...

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By using a cultured neuroblastoma cell line, the present authors recently showed that the N protein of virulent rabies virus fixed strain Nishigahara (Ni), but not that of the attenuated derivative Ni-CE, mediates evasion of induction of type I interferon (IFN). In this study, to determine whether Ni N protein indeed fulfills this function in vivo, the abilities to suppress IFN responses in the mouse brain of Ni-CE and the virulent chimeric virus CE(NiN), which has the N gene from Ni in the genetic background of Ni-CE, were compared. It was demonstrated that CE(NiN) propagates and spreads more efficiently than does Ni-CE in the brain and that IFN response in brains infected with CE(NiN) is weaker than in those infected with Ni-CE. It was also shown that amino acids at positions 273 and 394 in the N protein, which are known as pathogenic determinants, affect the ability of the viruses to suppress IFN response in the brain. These findings strongly suggest that, in the brain, rabies virus N protein plays important roles in evasion of innate immune responses and thereby in efficient propagation and spread of virus leading to lethal outcomes of infection.