Heterogeneity of BamHi DNA fragments B and E in several HSV-1 strains and recombinants.

The restriction cleavage sites of the BamHI-B and BamHI-E DNA fragments of several Herpes simplex virus type 1 (HVS-1) strains were mapped. These fragments are situated at the ends of the long unique regions and share homologous sequences in the repeat components (TRL and IRL) of the genome. All the strains analyzed were found to have deletions in the Hpal-P fragment, situated in the BamHI-B fragment. Five strains were further analyzed and the deletions were located in the Smal-A fragment (within the Hpal-P fragment). The BamHI-E fragment of four recombinants (obtained by recombination between the HFEM genome and the BamHI-B fragment or part of it from the HSV-1 F strain) were almost identical but differed from another strain [NIH(LP)]. Comparison of the BamHI-B and the BamHI-E fragments of the same strain revealed that the fragments were not identical in all cases.