Drosophila C virus cycle during the development of two Drosophila melanogaster strains (Charolles and Champetières) after larval contamination by food.

Drosophila C virus (DCV) cycle during Drosophila melanogaster development was studied after feeding contamination at the first, most sensitive, instar (L1). Two Drosophila strains were examined and compared. Presence of DCVC in apparently healthy animals (L3 larvae bred on a contaminated rearing medium and adults coming from larvae which were grown on medium containing DCVC) was demonstrated by biological tests. Using the immunofluorescence technique, DCV was exhibited in the diseased Charolles larvae, in the lumen of the digestive tract and in the basal part of gut cells which is in contact with the haemolymph. On the contrary, in Charolles larvae which seemed 'healthy', DCV was exhibited only in the lumen of the digestive tract at the apical boundary of the gut cells. But DCV typical protein capsid was not shown in the tissues of Drosophila L3 and adults. However, C virus remained in Drosophila tissues even after host metamorphosis and would seem to interact with Drosophila cells. Hypotheses are proposed concerning the intracellular state of Drosophila C virus in this case.