10.5 Transgenic Animals

. Transgenic Animals In early days selective breeding methods were carried out to improve the genetic characteristics of live stock and other domestic animals. With the advent of modern biotechnology it is possible to carry out manipulations at the genetic level to get the desired traits in animals. Transgenesis is the process of introduction of extra (foreign/exogenous) DNA into the genome of the animals to create and maintain stable heritable characters. The foreign DNA that is introduced is called the transgene and the animals that are produced by DNA manipulations are called transgenic animals or the genetically engineered or genetically modified organisms. The various steps involved in the production of transgenic organisms are • Identification and separation of desired gene. • Selection of a vector (generally a virus) or direct transmission. • Combining the desired gene with the vector. • Introduction of transferred vector into cells, tissues, embryo or mature individual. • Demonstration of integration and expression of foreign gene in transgenic tissue or animals. Transgenic animals such as mice, rat, rabbit, pig, cow, goat, sheep and fish have been produced (Fig. . ) .