Genetic heterogeneity and potential recombination across hosts of Gyrovirus galga1 in central and eastern China during 2021 to 2024.

Gyrovirus galga1 (GyVg1), formerly known as AGV2, was initially identified in chickens in southern Brazil. The prevalence of GyVg1 from 2021 to 2024 in 28 out of the 63 poultry farms located in Jiangsu, Anhui, Henan, Hunan, Shandong, and Hubei provinces in eastern and central China was detected via PCR. The complete genomes of the 28 strains were sequenced and exhibited a full length of 2,376 bp. Similarity analysis of these strains did not suggest definite correlation with evolutionary branching and geographical distribution. Compared with the reference GyVg1 strains, HN2202 shared the highest similarity of 99.71% with HLJ1511 (chicken-originated) from northeastern China in 2015 to 2016. Recombination analysis revealed that AH2102 was a potential recombinant of peafowl-originated HN2019-PF1 and chicken-originated HLJ1506-2, whereas HN2304 was a recombinant of peafowl-originated HN2019-PF1 and the Hungarian ferret strain G13. Mutation site analysis of the capsid protein revealed that highly mutated regions occurred between sites 288 to 316 and 383 to 419. These results indicate that GyVg1 may have undergone an interspecies transmission, which involved complex mutations and recombination. This study may provide a reference for subsequent investigations targeting the molecular epidemiology and viral evolution of GyVg1.