In this technique, the endogenous gene is removed and exchanged for a mutated version, which is introduced. This mutated version can remove the entire sequence of the gene , which is most convenient.
The process to obtain modified individuals usually takes months, although they have the advantage of being very specific. The most striking case is that of the Knockout mouse , which has one or more of its genes inactivated by genetic engineering to understand the role of a gene that has been sequenced.
The first Knockout mouse was produced between 1987 and 1989 by Oliver Smithies, Mario R. Capecchi and Martin Evans , an achievement for which they received the Nobel Prize in Medicine in 2007. Most of the methods for generating mice are patented in the United States (USA). ).





