Mutability studies in two Drosophila melanogaster isogenic stocks, endemic for C picornavirus and virus-free.

A virus-free Drosophila stock was obtained by outer disinfection of eggs from DCV-contaminated females. The healthy flies exhibited 3 times less lethal mutations on the X chromosome than did the diseased flies. In addition, on X and 2nd chromosomes, the mutability of the infected males was 2-3 times lower than that of the infected females. The natural viruses of Drosophila are partially responsible for the rate of mutations occurring in the wild populations of this insect.