Why genetically modify animals?
A range of benefits is sought from genetic modification of animals. Most work is basic or applied medical or biological research, aimed at understanding gene function and regulation, or studying human or animal disease. The ability to replace or alter individual genes, or delete them, can assist in investigating the natural functions of a gene in health and disease, the factors within the body that control it or interact with it, and the interplay between genes and external factors, such as diet or environment. Much experimental genetic modification is done on cells, plants or simple organisms, such as the nematode worm, C. elegans – and such alternatives are used in preference to vertebrate (or complex invertebrate) animals wherever possible. The following are some examples of the benefits that can come from using genetically modified mice and other vertebrate animals: (i) Use of laboratory animals – mainly mice The ability to insert or delete genes in the genomes of mice has assisted
