High frequency recombination between homologous baculoviruses in cell culture

The frequency of recombination between homologous baculoviruses was investi gated in cell culture upon coinfection with two Autographa californica nucl eopolyhedrovirus (AcMNPV) recombinants. These parental recombinants differe d at two loci, separated by 20 kb, each carrying a different marker. The pr ogeny recombinants generated by homologous recombination were easily distin guishable by the presence or absence of these markers. The mean percentage of the newly generated recombinants relative to a single locus varied betwe en 23 and 41%, depending on the multiplicity of infection used for coinfect ion. These results provide further evidence that homologous recombination o ccurring during baculovirus replication is a highly frequent event.