| abstract |
The present invention relates to the production of transgenic cattle comprising genetic modifications that cause inactivation and reduction of expression of endogenous antibodies and expression of heterologous antibodies, preferably human antibodies. This is achieved by inactivation of IgM H chain expression and optionally inactivation of Ig L chain expression and the introduction of artificial chromosomes which additionally result in the expression of antibodies other than bovine, preferably human antibodies.n n n n Heterologous antibodies, transgenic animals, ungulates. |