Genetic Studies with Herpes Simplex Virus Type 1. The Isolation of Temperature-sensitive Mutants, their Arrangement into Complementation Groups and Recombination Analysis Leading to a Linkage Map

SUMMARY Nine 5-bromodeoxyuridine-induced temperature-sensitive (ts) mutants were isolated from stocks of a syncytial plaque type mutant (syn) itself derived from the non-syncytial wild-type (syn +) of the glasgow strain 17 of herpes simplex virus type 1. The nine ts mutants have been assigned to eight cistrons on the basis of different complementation tests. Non-syncytial revertants isolated from the original ts syn mutants were used in reciprocal three-factor crosses of the type: tsX syn × tsY syn + and tsX syn + × tsY syn. With recombination data from these crosses a linkage map has been constructed. The provisional map which locates nine cistrons is linear and spans about 25 recombination units. The regular occurrence of plaques with mixed syn/syn + morphology in the progeny from crosses is reported.