9. GENERATION OF MOUSE MODELS FOR GENE THERAPY

Normally, gene therapy like any other administration of a new drug has to be tested in animal model, before clinical application on human.  Mice are good candidates for administering and studying the effect of new drugs. The mice have to be prepared in way to generate genetically manipulated mice, for example that carry or lack a specific gene. These mice provide tools to analyze the function of new genes in a whole organism environment and provide a model of a human disease.

The introduction of any gene to be incorporated within the genome, form what is known as transgenic mice. Therefore, it is possible to introduce specific gene together with promoter region, which will be expressed in specific tissue and forming the final protein product. 

Normally the gene of interest is cloned and constructed then injected into the pronuclei of fertilized mouse eggs, leading to the integration of this DNA into the mouse genome. The injected eggs are transplanted into female.  Expression of the gene and any resultant phenotypic changes can then be studied. (Figure 15) Transegenic mice are normally used in gene therapy to show the expression targeting types and longevity of the gene expression (Tsukui, 1996).