NEW GENOTYPES OF TT VIRUS (TTV) AND A GENOTYPING ASSAY BASED ON RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM

A phylogenetic analysis, using the open reading frame 1 sequence of 93 TT viruses (TTV) obtained from various geographical areas, indicated that the virus could be classified into six different genotypes includ ing three hitherto unreported genotypes, The high reliability of the s ix clusters was confirmed by bootstrap analysis. On the basis of these sequence data, a new simple genotyping assay based on a restriction f ragment length polymorphism of TTV was developed. Using the enzymes Nd eI and PstI, followed by cleavage with NlaIII or MseI, it was possible to distinguish between the six TTV genotypes, This system will provid e the framework for future detailed epidemiological and clinical inves tigations. (C) 1998 Federation of European Biochemical Societies.