Diversity of populations of Deformed wing virus in the honeybee (Apis mellifera) pupae overtly infected by injection of DWV virus preparations from overtly and covertly infected honeybees to haemolymph.

Experiment was designed (i) to analyse the strain composition of Deformed wing virus (DWV) populations in covertly and overtly infected honeybees (Apis mellifera) from Varroa-free and Varroa-infested colonies, and (ii) to determine abundance of the DWV strains following direct injection of the DWV preparations from covertly and overtly infected bees to the bee pupae haemolymph in the absence of Varroa destructor mites. Experiment included isolation of DWV preparations from the following bees: covertly-infected bees from Varroa-free colony, covertly infected bees exposed orally to the Varroa-selected DWV strains, and the overtly infected Varroa-exposed bees. Honeybee pupae were experimentally injected with those DWV preparations and sampled 4 days post injection following development of overt DWV infection. A series of the DWV cDNA fragment covering complete DWV genomic RNA sequences were amplified by RT-PCR using RNA extracted from virus preparations and the injected pupae. The cDNA preparations were sequenced using next generation(Illumina HighSeq 2000) paired-end sequencing to obtain data on the DWV strain composition.