FIG. 2.

(A) Autoradiograph of a Southern blot of a 0.8% agarose gel showing the results of hybridizing radiolabeled HindIII E (isolated from a plasmid [11]) to the HindIII products of MHV-68 and MHV-76 DNAs and three MHV-68 cosmids (cA8, cA4, and cA13) and one MHV-76 cosmid (cM1) containing the left end of the genome. The HindIII E fragment (6,155 bp) is indicated. (B) PCR analysis of the MHV-68 and MHV-76 genomes. PCR amplification was performed on viral DNA templates using primers specific for M1, M2, M3, M4, and gp150 as indicated. Reaction products were analyzed on a 1% agarose gel. Molecular size markers and their sizes in kilobase pairs are indicated to the left. (C) Schematic diagram (not to scale) showing the structures of the left ends of the MHV-68 and MHV-76 genomes. The open arrows indicate protein-coding regions, and the small arrowheads indicate the vtRNA genes. The open rectangle in MHV-76 indicates residual M4 sequence. TRs, terminal repeats.