MOLECULAR CHARACTERIZATION OF TWO NOVEL RAT MINUTE VIRUSES IN TAIWAN

Rodent parvovirus infection is one of the common viral problems in laboratory rodent colonies. In this study, two new parvoviruses were identified in naturally-infected rats from two different research colonies in Taiwan. The genomic nucleotide sequences and the predicted amino acid sequences of proteins for these two viruses were compared to the previously characterized rodent parvoviruses. The two newly identified viruses were most closely related to each other, also closely related to two variants of rat minute virus (RMV; RMV-1 and RMV-2), and distinct from but closely related to Kilham rat virus and H-1 virus. These two viruses were significantly different from variants of rat parvovirus (RPV; RPV-1 and RPV-NTU1). Phylogenetic data also supported that these two new viruses are variants of the RMV species. These two newly identified viruses were designated RMV type National Taiwan University 1 (RMV-NTU1) and RMV type National Taiwan University 2 (RMV-NTU2). RMV-NTUs are the first molecularly characterized RMV variants identified in Asia.

Molecular characterization of three newly recognized rat parvoviruses

Rodent parvoviruses have been documented to interfere with both in vivo and in vitro research. In this study, three rat parvoviruses distinct from previously characterized rodent parvoviruses were identified from naturally infected rats obtained from four discrete sources. These three newly recognized parvoviruses were designated rat minute virus (RMV)-1a, -1b and -1c. In this study, the genomic nucleotide sequence and the predicted amino acid sequences of proteins for each of the three RMV-1 variants and Kilham rat virus (KRV) were determined and compared with previously characterized rodent parvoviruses. The three RMV-1 variants were shown to be closely related to each other, to be distinct from but closely related to KRV and H-1 virus, and to be significantly different from the previously identified rat parvovirus isolate, RPV-1a.