Chimeric or transgenic animal and process for screening pharmaceutical products.

摘要

In a process for specific replacement of gene, esp. by DNA targetting, the DNA being inserted consists of a part of a gene which can be made functional (or more efficient) when combined with complementary to form a complete recombinant gene in the genome of a eukaryotic cell. The new features are that (1) the insertion site is in a chosen receptor gene contg. the complementary gene; (2) eukaryotic cells are transfected with a vector contg. an insert consisting of the insert DNA and 2 flanking sequences homologous to two genomic sequences adjacent to the insertion site; (3) the inserted DNA is heterologous with respect to the receptor gene and (4) the flanking sequences make up complementary DNA so that, by homologous recombination with the corresp. sequences of the receptor gene, a complete gene is reconstructed in the genome of the eukaryotic cell. Also new are (1) plasmids for this process; (2) transformed eukaryotic cells and (3) transgenic animals in which one copy of a gene (present at least twice) has been inactivated by insertion of a different gene.