Reverse transcription coupled with polymerase chain reaction and restrictio
n enzyme analysis was used to characterize 12 Drosophila C virus isolates f
rom geographically different regions. A 1.2-kb fragment was amplified from
cDNA and profiles from digestion with 20 restriction enzymes were generated
. Analysis of the restriction fragment data gave estimates of nucleotide di
vergence of 0-10% between isolates. The isolates were grouped on the basis
of genetic distance estimates derived from the restriction data. For the is
olates from which a single genotype could be purified, a geographical patte
rn in the distribution of viral genotypes was identified. The 4 Moroccan is
olates were very closely related to each other, differing in only 1 restric
tion profile. The 2 Australian isolates were each other's closest relatives
, as were the 2 isolates first recovered in France. The PCR-RFLP technique
used in this study has provided us with a simple procedure which can be use
d to characterize DCV isolates. A single enzyme, Tag I, generated 5 distinc
t and diagnostic restriction fragment patterns, which allowed easy assignme
nt of isolates to one of the five viral genotypes identified in this study.
(C) 1999 Academic Press.