Fig. 1.

Detection of ABBV-1 from persistently infected DEF using western blot, IFA, RT-qPCR and virus titration. For panels a), b) and c), DEF were incubated with either the brain homogenate from an ABBV-1 positive goose or control medium, and monitored for potential ABBV-1 replication using western blot and IFA. a Western blot showing detection of ABBV-1 N protein in lysates from infected DEF but not in uninfected control DEF culture. β-actin was detected in both infected and control DEF cultures. b and c IFA of control and infected DEF cultures, respectively, using a primary antibody against ABBV-1 N protein (green) and counterstained with DAPI (blue). Scale bar, 100 μm. For panels d, e and f, DEF were infected with cell-culture harvested ABBV-1 and monitored for ABBV-1 replication using RT-qPCR, western blot, and virus titration. D) RT-qPCR of DEF infected with ABBV-1 over the first seven passages. E) Western blot of ABBV-1-infected DEF at passages 1–3, 6–8 and 11–13. F) Virus titration of ABBV-1-infected DEF at passages 6–8 and 10–12