“…There is conclusive evidence for classical and non-classical MHC class I (MHC-I) or MHC class IIB (MHC-IIB) in Galliform species such as the chicken, the turkey ( Meleagris gallopavo ), the black grouse ( Tetrao tetrix ), and the golden pheasant ( Chrysolophus pictus) [5,36,44,45,46,47,48,49]. Possessing both classical and non-classical MHC genes appears to be a taxonomically widespread phenomenon because it has been observed in primates, fish, amphibians, and reptiles [50,51,52,53,54]. Classical MHC genes are usually highly expressed, polymorphic, and have a well-established function in presenting antigens to T-cells [55].…”