INTERTYPIC COMPLEMENTATION AND RECOMBINATION BETWEEN TEMPERATURE-SENSITIVE MUTANTS OF HERPES-SIMPLEX VIRUS TYPE-1 AND TYPE-2

In an attempt to identify functionally common and type-specific genes in the genomes of herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), intertypic complementation and recombination experiments between temperature-sensitive (ts) mutants of these viruses were undertaken. Intertypic complementation was carried out with 7 HSV-1 ts mutants representing 5 complementation groups and 8 HSV-2 ts mutants representing 5 complementation groups. Efficient complementation was detected with most HSV-1 + HSV-2 ts mutant pairs, indicating extensive interchangeability of gene functions between HSV types 1 and 2. Progeny analysis of complementation yields demonstrated that complementation was symmetric, i.e., equal amounts of both HSV-1 and HSV-2 ts mutants were produced. HSV-1 wild-type virus was also able to complement HSV-2 ts mutants efficiently. Intertypic recombination experiments demonstrated that heterologous mutant pairs which failed to complement also failed to recombine efficiently.