Choice of transgenic animal
First and foremost is the selection of animal species in which gene of interest is to be transferred. Whatever is the goal of production of transgenic animal production, mice in which specific mutations have been deliberately introduced, have often served very useful models for studying human genetic diseases such as cystic fibrosis. In some cases, differences between mice and human mean that the effects of the introduced mutation are not the same as in the human genetic disease. Yet this model served the science in knowing, how a gene and its regulatory elements are working in an animal system, the impact of transgenes on health and productivity of the animal, and the level of recovery of recombinant protein including the workout cost of therapeutic protein to alter the strategies in the target farm animal species. When one talks about the choice of farm animal species, it is to be seen that what is the purpose of production of a transgenic animal and in which tissue one wants to get the recombinant protein likely to express itself? If the protein is secreted in milk, dairy animals like goats and cattle are preferred, while for xenotransplantation, pig and sheep are the ideal species.