Molecular Characterization ofDrosophilaC Virus Isolates

Abstract

Reverse transcription coupled with polymerase chain reaction and restriction enzyme analysis was used to characterize 12DrosophilaC virus isolates from 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 divergence of 0–10% between isolates. The isolates were grouped on the basis of genetic distance estimates derived from the restriction data. For the isolates from which a single genotype could be purified, a geographical pattern in the distribution of viral genotypes was identified. The 4 Moroccan isolates were very closely related to each other, differing in only 1 restriction 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 used to characterize DCV isolates. A single enzyme,TaqI, generated 5 distinct and diagnostic restriction fragment patterns, which allowed easy assignment of isolates to one of the five viral genotypes identified in this study.