Evolutionary and genotypic analyses of goose astrovirus

Based on 183 complete genome sequences of Goose Astrovirus (GAstV), this study systematically elucidated the molecular epidemiological characteristics and evolutionary patterns of the virus. Through whole-genome phylogenetic analysis, GAstV was clearly classified into two major groups: GAstV-I (GI) and GAstV-II (GII), which were further subdivided into six distinct subgroups with significant genetic divergence. Spatiotemporal dynamic analysis revealed that the virus has spread extensively to 17 provinces in China over the past decade. Notably, 27 recombination events were identified, indicating that genetic recombination serves as a key driver of GAstV evolution. 210 specific amino acid variation sites were detected in the capsid protein, among which the characteristic amino acid deletions at positions 652-653 and 706 could serve as reliable molecular markers for the GI a and GI b subgroup. These findings not only deepen our understanding of the molecular characteristics and evolutionary mechanisms of GAstV but also provide a profound theoretical basis for establishing precise viral surveillance systems and formulating effective prevention and control strategies.