Fig. 1

Characterization of growth of DHAV-3 in DEF cells. a Observation on formation of CPE in DEF cells. The picture was taken at 72 h after inoculation with the 10th passage of YDF120 and C-GY. b Assays on formation of plaques in DEF cells at 72 hpi. The 5th cell passages of DHAV-3 YDF120 and C-GY were used as inocula. The infected cells were stained with crystal violet, and viewed with direct light. c Analysis on expression of viral protein by immunostaining of DEF cells at 36 hpi. The 5th cell passages of DHAV-3 YDF120 and C-GY were employed to infect DEF cells. Viral protein expression was analyzed with specific chicken antisera against DHAV-3 C-GY and a FITC-conjugated goat anti-chicken serum (green). Bar = 50 μm. d Quantification of viral RNA copies in DEF cells at 72 hpi. RNA copies were detected by qPCR, and the results were shown for the first to tenth passages of DHAV-3 YDF120 and C-GY