Novel Gammacoronavirus Species Identified in Poultry from Southern China: A Genomic Characterization

Gammacoronaviruses (γ-CoVs) are widespread in avian populations. This study reports the identification and genomic characterization of a novel γ-CoV species, designated DCoV-JX621, from a live poultry market in southern China. The complete genome of DCoV-JX621 is 29,437 nucleotides long with 40.2% GC content and exhibits significant divergence from known coronaviruses, particularly in the spike (S) protein and untranslated regions (UTRs). The 5’ UTR displays low sequence similarity (61.32%) to other DCoVs, while the 3’ UTR contains a conserved octanucleotide motif. Notably, DCoV-JX621 encodes six accessory proteins and harbors an 819-nt region downstream of the N protein with no detectable homology to known γ-CoV proteins. It lacks a functional NSP1 but possesses 14 NSPs similar to Goose coronavirus. Phylogenetic analysis revealed a distinct evolutionary lineage for DCoV-JX621, suggesting its recent emergence through recombination or other evolutionary mechanisms. The discovery of this novel γ-CoV species underscores the ongoing evolution and diversification of gammacoronaviruses in avian species.