Discrete virus factories form in the cytoplasm of cells co-infected with two strains of the segmented dsRNA virus, infectious bursal disease virus (IBDV), that subsequently coalesce

Abstract

word count: 250 12 Text word count: 4,977 13 14 Abstract 15The Birnaviridae family, responsible for major economic losses to poultry and aquaculture, are 16 non-enveloped viruses with a segmented double-stranded (ds)RNA genome that replicate in 17 discrete cytoplasmic virus factories (VFs). Reassortment is common, however, the underlying 18 mechanism remains unknown given that VFs may act as a barrier to genome mixing. In order to 19 provide new information on VF trafficking during dsRNA virus co-infection, we rescued two 20 recombinant infectious bursal disease viruses (IBDVs) of strain PBG98 containing either a split 21 present address: Mars Inc. 42dsRNA virus during a co-infection. Discrete VFs initially formed from each virus that 43 3 subsequently coalesced from 10 hours pi. We hypothesise that VF coalescence is required for 44 the reassortment of dsRNA viruses and the potential for reassortment increases later in the 45 replication cycle. This study provides new information that adds to our understanding of dsRNA 46 virus VF trafficking. 47 48

Ex vivo rescue of recombinant very virulent IBDV using a RNA polymerase II driven system and primary chicken bursal cells

“…Both strategies failed and were quickly abandoned (data not shown). Instead, DF-1 cells, which have been previously used for IBDV rescue 23 , 30 , were chosen as an intermediate host to rescue the recombinant viruses Cu-1 (rCu-1) and vv (rvv).…”