Turkeys possess diverse Siaα2-3Gal glycans that facilitate their dual susceptibility to avian influenza viruses isolated from ducks and chickens.

Avian influenza viruses (AIVs) circulating in wild ducks are rarely transmitted directly to chickens. Previous studies demonstrated that chickens possess fucosylated and/or sulfated α2,3 sialosides on their tracheal epithelia, whereas intestinal epithelia of ducks express canonical α2,3 sialosides. Turkeys, the third major poultry species in the world, are known to show broad susceptibility to various avian influenza viruses. To elucidate the molecular basis of the broad susceptibility of turkeys to duck and chicken AIVs, we characterized various receptors for AIVs on their tissues. The experimental infection of turkeys demonstrated their dual susceptibility to duck and chicken AIVs. Further, comprehensive histochemical analyses using lectins, anti-glycan antibodies, and recombinant hemagglutinins, combined with glycosidase digestions, identified the presence of fucosylated and/or sulfated in addition to canonical α2,3 sialosides on their respiratory epithelia. The receptor distributions in turkeys were consistent with their dual susceptibility to duck and chicken AIVs. Also, our findings suggested the potential roles of turkeys in interspecies transmission of AIVs from ducks to chickens.