This invention generally relates to methods for the production of antibody producingcells and antibodies in protooncogene expressing animals. The invention alsorelates to methods for the efficient production of antibodies specific for antigensthat are normally subject to immunological constraints such as self tolerance.The invention further relates to the production of antibody producing cellsand antibodies without the need for the conventional fusing of antibody producingB cells with a myeloma fusion partner.