Restriction map and southern analysis of the bean golden mosaic virus genome.

A restriction map showing 5'-3' polarity for two species of circular single-stranded (ss) DNA from bean golden mosaic virus (BGMV) is presented. The two viral single-stranded DNAs, which are very similar in size, were separated by prolonged agarose gel electrophoresis at low voltage. Hybridization analysis using probes made from these separated DNAs shows they are largely dissimilar in nucleotide sequence except for a common region of high homology which has been mapped to a unique location on each species. Molecular clones of BGMV DNA from restriction fragments comprising all of one of the two DNAs and part of the other were used to confirm the restriction and hybridization analysis. These results provide further evidence consistent with the hypothesis that BGMV and other geminiviruses possess divided genomes with two components of nearly equal size.