Genomic characterization of Molluscum contagiosum virus type 1: identification of the repetitive DNA sequences in the viral genome.

The genomes (188 kbp) of the prototype Molluscum contagiosum virus type 1 (MCV-1) and a variant strain (MCV-1v) were characterized by construction of the physical maps of the viral DNA for the restriction enzymes BamHI, ClaI, EcoRI, and HindIII using a defined gene library harboring the DNA sequences of the MCV-1 genome and by DNA-DNA hybridizations. It was found that the genomes of both MCV strains are identical, with the exception of very few changes in the DNA fragmentation patterns of restriction endonuclease BamHI as a consequence of naturally occurring nucleotide exchanges in the genome of the variant strain. Detailed hybridization experiments revealed the existence of repetitive DNA sequences, which are located within the terminal regions of the viral genome at the map coordinates 0 to 0.027 and 0.973 to 1.