ABSTRACT
This chapter addresses the establishment and maintenance of lines of genetically modified (GM) rodents and their phenotypic characterisation. The basis of every GM strain is a founder animal that carries and transmits the genetic modification to the next generation. The breeding performance of GM animals may differ from that of wild-type counter-parts, and consequently it should be carefully monitored. Software for breeding registration programmes or colony management programmes are available commercially. The obvious aim of phenotyping an animal is to identify new traits either for welfare assessment or scientific use. The housing and transport of GM animals must be carried out within the framework of European and national laws and regulations. Technological advances and demands for more complex animal models pose challenges for the field of laboratory animal science. Special attention should be given to the introduction of animals from other establishments into a colony.
