Molecular genetics of herpes simplex virus. III. Fine mapping of a genetic locus determining resistance to phosphonoacetate by two methods of marker transfer.

We have transferred a genetic locus determining resistance to phosphonoacetic acid (PAAr) from one herpes simplex viral genome to another by two methods of marker transfer. One method requires recombination between an intact DNA molecule and a restriction endonuclease DNA fragment, whereas the other requires repair of a partial heteroduplex formed between the two DNA molecules. These two methods mapped the PAAr locus between positions 0.45 and 0.53 map units on the physical map of the viral DNA. Fine mapping of the PAAr locus showed that it maps at or near an EcoRI restriction endonuclease site at either 0.46 or 0.49 map units. We also describe and compare the two methods of marker transfer.