Production of Transgenic Animals: Practical Problems and Welfare Aspects

Summary

Transgenic technology has been used to produce animals as suitable in vivo systems to study human disease, mammalian gene expression and regulation, as well as finding applications in zootechnology, pharmacology and medicine. The past few years have seen a rapid proliferation in the creation of genetically engineered mice as animal models of human diseases, representing an unique and valuable genetic resource.

However genetic manipulation can alter a balanced genotype and produce unpredictable effects.

In order to define, standardise and validate the new transgenic models, it is fundamental to avoid environmental contamination, and to provide special care in terms of space, health management and welfare assessment. Particularly for rodents, the facility in which the animals are kept must be centralised, physically contained and microbiologically controlled. All the animals must be microbiologically defined (specified pathogen free, SPF). Active environmental control, health management, and medical surveillance of personnel must be performed on a constant basis.

Newly generated animal models should be observed following simple but essential criteria. These observations should also be quantifiable and reproducible. Following the ontogenesis of behaviour is a good strategy to recognise and assess deficits before these simple responses are integrated by homeostatic and adaptive mechanisms.

Screening conducted from birth will allow any innate deficits to be identified, estimated and quantified. This screening would also provide the basis for modulating the environment, housing and caging conditions, as well as producing useful information which to date is not included in most scientific publications.