ABSTRACT
This chapter focusses on institutions that were specialized in breeding experimental animals. It traces a long trajectory starting in the 1920s in the breeding facilities of the German Research Foundation, the basis for the first German research programme in comparative medical genetics. In order to outline the emergence of comparative genetics, the chapter focuses on the German geneticist Hans Nachtsheim. It deals with the foundation of the German Mouse Clinic in 2001. The chapter discusses the continuity of a specific research tradition, from early agricultural genetics to today's genomics. Udo Ehling was ambitious, and in order to exhibit his radiobiological skills he decided to try to establish a new mutagenesis test on the basis of dominant mutations. A crucial step was taken when Ehling and his group introduced a new chemical compound in the toxicogenetic experiments at the Experimental and Education Centre for Radiation Protection (GSF) animal house: ethylnitrosourea (ENU).
