New type of cytoplasmic polyhedrosis virus isolated from mosquitoes in China

0507BS3 virus was isolated from a mixed pool of Culex sp.and Anopheles sp.collected in Kashi,Xinjiang,China.0507BS3 virus could cause cytopathic effects on C6/36 cells but not on Vero and BHK-21 cells.Viral particles had no envelope and appeared round with diameter of about 60nm(n=20).Viral capsid was composed of a single layer and a central core.Capsomeres on the surface of capsid were clearly visible.Electrophoresis of viral genome showed a profile of 10 double stranded RNA(dsRNA) segments.Sequencing of the tenth segment revealed the length of 964bp(GenBank ID:FJ150869).A single open reading frame(ORF) was found and encoded a protein of 275 amino acids with a molecular mass of 30.8kDa.The nucleotide sequence had no similarity with any other viral genomic sequences,but the deduced amino acid sequence significantly matched the polyhedrin genes of cytoplasmic polyhedrosis virus(CPV) in some sections.A phylogenetic tree was constructed to compare the polyhedrin gene sequences of all CPV types in GenBank.The tree demonstrated that 0507BS3 virus was only distantly related to the other CPV types and belonged to a new CPV type.