CLONING, RESTRICTION-ENDONUCLEASE MAPPING AND PARTIAL SEQUENCE-ANALYSIS OF THE GENOME OF HUMAN HERPESVIRUS-7 STRAIN JI

Human herpesvirus 7 (HHV-7) is a recently isolated herpesvirus that ha s been shown to be related to human cytomegalovirus and human herpesvi rus 6 and to be a member of the betaherpesvirus subgroup, Here we repo rt the cloning, restriction endonuclease mapping and partial sequence analysis of HHV-7 strain JI DNA. Virus particles were obtained from th e supernatant of infected SupT1 cells, the DNA isolated by proteinase K treatment-phenol extraction, and full-length viral DNA was purified and isolated on a pulsed-field gel. Aliquots of this highly purified m aterial were treated in the following ways: (i) sonicated and end-repa ired to create short randomly sheared fragments for cloning into M13mp 18-Smal vector DNA; (ii) cut with EcoRI for cloning into EcoRI-cut la mbda ZAPII or lambda DASHII vectors; (iii) cut with BamHI for cloning into BamHI-cut lambda ZAP-Express or lambda DASHII vectors. Partial nu cleotide sequencing of the M13 clones followed by detection of open re ading frames and their translation allowed the identification of homol ogues through PASTA searches of the database. Relevant M13 clones were used as probes to isolate corresponding lambda phage clones, which co uld tentatively be mapped to the genome on the basis of presumed genet ic collinearity between HHV-7 and HHV-6. Genomic 'walking' between Eco RI and BamHI lambda genomic libraries enabled overlapping neighbouring clones to be identified and mapped. Each of these clones was analysed to map BamHI, EcoRI, Sail, SmaI and XhoI restriction endonuclease sit es to provide complete endonuclease maps for the entire genome.