DISCRIMINATION OF HEPATITIS-G VIRUS GBV-C GEOGRAPHICAL VARIANTS BY ANALYSIS OF THE 5'-NONCODING REGION

We have investigated the ability of different subgenomic fragments to reproduce the phylogenetic relationships observed between six complete genome sequences of GBV-C/hepatitis G virus (HGV). While similar rela tionships were observed following analysis of part of the 5' non-codin g region (5'NCR), for the coding region they were not accurately repro duced for some large fragments or for the majority of fragments of 300 or 600 nucleotides. Analysis of 5'NCR sequences from a large number o f isolates, including newly obtained sequences from Pakistan, Zaire an d Scotland, produced separate groupings of Asian, African and European /North American variants. These groupings are associated with specific polymorphisms in the 5'NCR, many of which were covariant and consiste nt with a proposed secondary structure for this region. The relatively low level of amino acid sequence variation observed between these geo graphically and phylogenetically defined groups of variants suggests t hat they are unlikely to display significant biological differences.