[Recombinant DNA and genetic manipulation, reality and fantasy (author's transl)].

Genetic manipulation deliberately tries to influence the progeny of a living organism to achieve a human purpose. Well-known instances are artificial insemination and embryo transfer. The species barrier is not broken in this procedure and a surrogate mother is required in every case. In frogs, the nuclei og a number of fertilized ova may be replaced by the nuclei of vegetative cells of a single frog (a) and thus produce a clone of identical frogs (a). This is impossible in mammals. Parts of plants and even cultures of vegetative plant cells may develop into complete plants. This fact is gratefully used for the rapid propagation of useful hybrids. The recombinant DNA procedure is a method by which particles of any DNA can be multiplied in a culture of bacteria. This DNA can consequently be cloned. The basic principles of the procedure are discussed. When the recombinant DNA technique is used, the species barrier is passed. It can only be used, however, to influence the heritable characteristics of unicellular organisms or vegetative cells in cultures. This may possibly include plants. The risks run by the investigator using this technique are much smaller than those to which he is exposed in the case of pathogenic bacteria. When non-pathogenic bacteria showing a high degree of biological containment are used, the hazard of spreading in the environment is small. This problem undoubtedly merits further attention in other organisms. Mammals cannot be 'clonized' or freaks produced using recombinant DNA procedures.