RIG-I is present in ducks and pigeons, but apparently absent in chickens. (A) Hybridization of a multiple exon duck RIG-I probe to HindIII and XbaI-digested genomic DNA from four White Pekin ducks and two White Leghorn chickens. (B) Hybridization of a single exon duck RIG-I probe to PstI, NdeI, and SacI digested genomic DNA from duck, chicken, and pigeon. (C) Hybridization of a single exon duck MDA5 probe to same blot.