Résumé
The methods of nuclear transfer in mammals have created many new opportunities in biology, medicine, and agriculture. Potential uses of these technologies include production of animal organs and tissues for transplantation to human patients (xenotransplantation), improvement of livestock, provision of human cells for treatment of degenerative diseases (stem cell therapy), and analysis of specific gene product function and the mechanisms that regulate gene expression. These applications are discussed in detail elsewhere (1, 2). Many of these nuclear transfer applications introduce genetic changes in cells before their use as nuclear donors in order to genetically modify the offspring. For example, research is focusing on producing genetically modified pigs so that the organs and tissues will not be rejected by human patients following xenotransplantation.