Why did scientists develop cloning techniques?
Scientists were initially interested in SCNT as a means of determining whether all the genes in an organism’s genome remain functional even after most of them have been switched off as a developing organism’s cells assume their specialized functions as blood, bone, muscle, and so forth. The ability of scientists to stimulate the DNA in a nucleus from a fully differentiated cell to revert to a condition comparable to the DNA in a newly fertilized egg and to begin the process of embryonic development demonstrated that all the genes remain viable in differentiated cells even though only a few genes are actually expressed in each cell. Commercial interest in animal cloning centres on replicating large numbers of genetically identical animals, especially those derived from a progenitor which has been modified genetically. In this fashion, mice or other laboratory animals that exhibit particular conditions can be created for specialized studies, or herds of farm animals (such as goats, sheep
