Abstract: The transgenic non-human animals are constructed, in whose genome the coding sequences of one of the animal's endogenous immunoglobulin C? constant regions are replaced by human immunoglobulin C? constant region coding sequences. The transgenic animal is mouse, in whose genome the C?1 constant regions are replaced by the human immunoglobulin C? constant regions and the C? constant region is replaced by the human immunoglobulin C? constant region. The transgenic mouse yields humanized IgE-secreting B cells and antigen-specific humanized IgE after immunization. The transgenic animals are employed to prepare serum containing humanized IgE, antiserum containing antigen-specific humanized IgE, and monoclonal antigen-specific humanized IgE antibodies by hybridoma and other technologies.

Abstract: Provided are transgenic non-human animals, in whose genome the coding sequence of one of the endogenous immunoglobulin C? constant regions is replaced by a human immunoglobulin C? constant regions coding sequence. One preferred transgenic animal is a mouse, in whose genome the C?1 constant regions are replaced by human immunoglobulin C? constant regions and the C? constant region is replaced by human immunoglobulin C? constant region. The transgenic mouse yields humanized IgE-secreting B cells and antigen-specific humanized IgE after immunization. Also provided are the applications of the transgenic animals for preparing serum which containing humanized IgE, antiserum which containing humanized IgE, and monoclonal antigen-specific humanized IgE antibodies by hybridoma or other technologies.