Abstract: The present invention provides a method for producing a transgenic (Tg) non-human animal capable of developing an enhanced humoral immune response against an antigen as compared to a non-transgenic control animal of the same species, comprising introducing into said non-human animal a genetic construct providing for enhanced MHC class I-related neonatal Fc receptor (FcRn) activity. Also provided a Tg non-human animal comprising a genetic construct providing for enhanced FcRn activity, as well as the use of such animal in a non-therapeutical method. Therapeutic genetic constructs and methods are also provided. The present invention further provides methods for producing immunoglobulins.

Abstract: Immunoglobulin G (IgG) transporting ruminant Fc receptor (FcRn) ?-chain DNA molecules, especially those of cow, dromedary and sheep (SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3) are disclosed. Protein expressed by said FcRn ?-chain DNA molecules are disclosed and include SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6. Vectors containing the ruminant IgG transporting FcRn ?-chain DNA molecules, and hosts transformed with such vectors are also included. Further, a method of producing colostrums or milk with enhanced levels of immunoglobulins or proteins fused to immunoglobulin ?-chains of FcRn interacting parts thereof is also disclosed.