Abstract: The present invention provides a method for obtaining diverse novel genes by inducing somatic cell homologous recombination at genetic loci in somatic cells. By controlling transcription activity of a gene that exists at a genetic locus in a eukaryotic organism cell wherein DNA homologous recombination is occurring at an arbitrary genetic locus, somatic cell homologous recombination is induced between said gene and a gene having a DNA sequence similar to said gene that exists in a region upstream of a transcription promoter, whereby it is possible to obtain diverse novel genes having a plurality of genetic information.

Abstract: The present invention provides a novel method for obtaining diverse antibodies as a result of markedly enhancing the somatic homologous recombination at an antibody locus in immunocytes. By putting immunocytes in which DNA homologous recombination is occurring at an antibody locus (for example, DT40 cells and the like) into contact and the like with histone acetylase inhibitor and the like (for example, trichostatin A and the like), thereby relaxing the chromatin structure at said antibody locus, somatic homologous recombination at an antibody locus is enhanced, and the production of diverse antibody molecules is made possible. The production of antibodies that bind specifically to antigens from cell populations in which the antibody molecules have been diversified by the enhancement of somatic homologous recombination is made possible by using an appropriate selection method (for example, beads coated with antigen and the like).