ABSTRACT
We conducted phylogenetic and restriction fragment length polymorphism (RFLP) analyses of 995 nucleotides within the hemagglutinin (H) gene open reading frame (ORF) of field isolates of 23 canine distemper virus (CDV) strains isolated from domestic dogs in Japan between 1982 and 1998. The phylogenetic analysis showed that Japanese field isolates could be separated into three groups. Eighteen out of the twenty-three strains constituted one cluster consisting of Japanese CDVs, four strains formed a second Japanese CDV group, and only one strain belonged to a group containing foreign CDV strains. By RFLP analysis using SspI, we could distinguish all the Japanese field isolates from the vaccine strains. Thus, the RFLP method is useful for differentiating the infections with field CDV strains from the vaccine strains in clinical cases.
Subject(s)
Distemper Virus, Canine/classification , Distemper Virus, Canine/genetics , Distemper/virology , Hemagglutinins, Viral/genetics , Polymorphism, Restriction Fragment Length , Amino Acid Sequence , Animals , DNA, Viral/isolation & purification , DNA, Viral/metabolism , Deoxyribonucleases, Type II Site-Specific/metabolism , Distemper Virus, Canine/isolation & purification , Dogs , Japan , Molecular Sequence Data , Phylogeny , RNA, Viral/isolation & purification , RNA, Viral/metabolism , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino AcidABSTRACT
Several studies have indicated that viruses require a specific cytoskeletal structure for replication in host cells. In this study, we examined the role of actin fiber in the replication of canine distemper virus (CDV), belonging to the Morbillivirus genus of the family Paramyxoviridae. For this purpose, we used two actin depolymerizing agents, cytochalasin-D (C-D) and mycalolide-B (ML-B). In Vero cells, C-D disrupted actin fibers distributed in the cytosol, but peripheral actin fibers remained intact. On the other hand, ML-B completely disrupted the actin fibers distributed in both areas. Treatment of Vero cells with C-D or ML-B inhibited the replication of CDV. Double staining of CDV-infected Vero cells with antibody to N-protein and rhodamine-phalloidin revealed the presence of N-protein in mid-cytoplasm. However, the N-protein was specifically localized at the submembrane region in the presence of C-D, whereas it was clustered in the presence of ML-B. Viral mRNA levels of N- and H-proteins were rather increased by treatment with C-D or ML-B. The treatment with ML-B strongly inhibited N-protein expression, whereas C-D only slightly inhibited N-protein expression. These results suggest that actin microfilaments distributed in the cytoplasm and on the membrane region in host cells may have a different role in the process of CDV replication.
