[Dynamics of the replication process of Akabane virus GZTS-1 strain in Vero cells]

To investigate the pathogenicity and replication dynamics of Akabane virus (AKAV) in Vero cells, we infected Vero cells with the genotype Ⅱ AKAV strain GZTS-1 and determined the viral titer. Viral copies in the cell supernatant at different time points post-infection were quantified by qPCR. Viral replication was observed by fluorescence microscopy and confocal laser scanning microscopy after indirect immunofluorescence assay (IFA). The results showed that AKAV GZTS-1 induced significant cytopathic effects (CPE) in Vero cells, and the viral titer demonstrated an overall upward trend. qPCR revealed that the viral copy number sharply declined at 24 h post-infection (hpi), increased to reach the peak at 48 hpi, dropped to the lowest level at 72 hpi, before rising again and maintaining high levels at 84 hpi and 96 hpi. Fluorescence microscopy and confocal laser scanning microscopy demonstrated weak fluorescent signals at 6 hpi, which persisted until 18 hpi. Distinct fluorescent dots appeared at 24 dpi, though with limited distribution. The fluorescent area gradually expanded, and extensive diffuse fluorescence was observed at 72 hpi, which persisted until 96 hpi with peak intensity. These findings underpin subsequent AKAV vaccine development and research on pathogenic mechanisms.