ANTIGENIC AND GENETIC COMPARISONS OF JAPANESE AND AUSTRALIAN SIMBU SEROGROUP VIRUSES - EVIDENCE FOR THE RECOVERY OF NATURAL VIRUS REASSORTANTS

The antigenicity and RNA genome structures of five Simbu serogroup bun yaviruses isolated in Japan and Australia were analyzed using monoclon al antibodies (Mabs) raised to Akabane (AKA) virus and oligonucleotide fingerprinting. The virion surface glycoprotein (G1) and the nucleoca psid (N) protein of heterologous viruses showed no reactivity to the M abs, while the AKA-derived anti-G1 Mab (2F1) reacted with Peaton virus and all three AKA anti-N Mabs reacted with Tinaroo (TIN) virus at alm ost the same antibody titers as the homologous virus. Oligonucleotide fingerprinting analyses indicated that the three RNA species of all th e viruses were unique and distinguishable. However, AKA and TIN viruse s exhibited very similar S RNA oligonucleotide fingerprints, while the L and M RNA fingerprints were quite different. The S RNA sequence of TIN virus has been determined and compared with that of AKA and Aino v iruses. The results revealed 95.1% S sequence homology between the AKA and TIN viruses. The antigenic and genetic comparisons of AKA and TIN viruses suggest that the two viruses may represent naturally occurrin g reassortant viruses. (C) 1997 Elsevier Science B.V.