Organization of the canine calicivirus genome from the RNA polymerase geneto the poly(A) tail

In recent years a wealth of data has become available about the calicivirus es that infect humans, as well as those which infect a range of animal spec ies, notably cats, rabbits, pigs and marine animals. However, in the two de cades since the earliest reports of calicivirus infection in dogs, very lit tle has become known about the epidemiology, pathogenicity and molecular bi ology of the caliciviruses that may infect canines, In 1990, a canine calic ivirus (CaCV) was isolated from a 2-month-old diarrhoeic domestic dog in Ja pan, This virus, which can be grown in cultured cells of canine origin, has the classic 'Star of David' morphology of caliciviruses, and the one major structural protein was shown to be immunogenic in dogs. In this study, a 3 .8 kb region of the genome of this CaCV isolate from the RNA polymerase gen e to the 3' poly(A) tail was cloned and sequenced, and phylogenetic analysi s was undertaken in order to establish the relationship of CaCV to other an imal and human caliciviruses. This CaCV isolate had a nucleotide sequence, genomic organization and phylogenetic position closest to, but clearly dist inct from, both feline calicivirus and San Miguel sea lion virus isolates, These findings suggest that CaCV represents a new clade of animal calicivir uses, presumably as a member of the recently proposed new genus Vesivirus.