THE USE OF S1 NUCLEASE TREATMENT OF HYBRID PCR PRODUCTS FOR THE DIFFERENTIATION BETWEEN PVY ISOLATES

A new strategy based on treating PCR hybrids with S1 nuclease was used to differentiate between two PVY isolates. Mixed denatured and anneal ed hybrid PCR products of two PVY isolates including a tested strain a nd a reference N strain were treated with S1 nuclease. Single-stranded mismatched regions were revealed by the S1 nuclease cleavage, yieldin g a characteristic pattern of bands in polyacrylamide gel by which vir us isolates could be matched. Sequence analysis of the relevant PCR pr oducts revealed that only part of the mismatched regions were cleaved by the S1 nuclease. Still, the distinct pattern of degradation product s enabled the differentiation between the PVY isolates. The general ap plication of this procedure for strain differentiation is discussed.