Evidence from recombinant bunyavirus studies that the M RNA gene products elicit neutralizing antibodies

Homologous virus genetic recombination has been demonstrated for snowshoe hare (SSH), La Crosse (LAC), Tahyna (TAH), Lumbo (LUM), and Trivittatus (TVT) viruses, members of the California (CAL) serogroup of bunyaviruses, as well as for Guaroa (GRO) virus, a member of the Bunyamwera serogroup. No heterologous virus genetic recombination has been obtained between GRO and LAC, SSH, TAH, or TVT viruses, although recombination has been demonstrated between TAH and LAC, SSH, or TVT viruses, as well as between LAC and TVT or SSH viruses. Not all the dual temperature sensitive ( ts ) mutant virus coinfections (e.g., the reciprocal crosses to those that gave recombinants), yielded the expected recombinant viruses. This paradox is discussed in relation to the conditions necessary to produce recombinant viruses. Eight new recombinant viruses (TAH/LAC/TAH, TAH/LAC/LAC, LAC/TAH/LAC, LAC/TAH/TAH, TVT/LAC/TVT, TVT/TAH/TVT, SSH/TAH/TAH, and SSH/TAH/SSH) have been characterized. Plaque reduction neutralization tests have been performed with seven of these eight viruses, and four recombinant bunyaviruses obtained previously (i.e. SSH/LAC/LAC, SSH/LAC/SSH, SSH/SSH/LAC, and LAC/LAC/SSH). The results obtained using antisera raised against prototype TAH, TVT, SSH, or LAC viruses indicate that one or both of the bunyavirus M RNA gene products (i.e., their glycoproteins G1 and G2) specify the antigenic determinants recognized in the neutralization test.