RECOMBINATION OF ALPHAVIRUSES IN MIXED IN FECTION OF CELL-CULTURES - VENEZUELAN EQUINE ENCEPHALOMYELITIS (VEE) AND KARELIAN FEVER (KF) VIRUSES RNA HYBRIDS IN THE REGION OF NUCLEOCAPSID AND ENVELOPE PROTEIN GENES

A recombination of the genomes of VEE and KF viruses, two alphaviruses of different serotypes, takes place in mixed infection of chick embry o fibroblasts and Vero cells with vaccine strain VEE-230 and KF-9298 s train. This recombination resulted in the production of recombinant vi rions with altered antigenic properties. Polymerase chain reaction (PC R) rapidly and effectively detected the hybrid sites of the genome in recombinant viruses. Short nucleotide sequences (approximately 20 n. p .) of a known primary structure in the RNA genomes, specifically react ing with the complementary PCR primers, were chosen as genetic markers . These data are the first experimental validation of the probable rec ombinant formation of alphaviruses in nature. They are in good agreeme nt with findings of the recombinant structure of Western equine enceph alomyelitis virus genome.