ABSTRACT

Our ability to manipulate the genome of whole animals has influenced the biological sciences in a most remarkable fashion. In two decades, manipulations of the genetic composition of transgenic animals have allowed researchers to address fundamental questions in fields ranging from production agriculture to biomedical research. In a host of transgenic animal models, basic research into the regulation and function of specific genes forged the way to

in vivo

genetic modifications that resulted in either the gainof-function of a transferred gene or the ablation of an endogenous gene product. Pioneering efforts in transgenic animal technology have markedly influenced our appreciation of the factors that govern gene regulation and expression, and have contributed significantly to our understanding of the genetic bases of human development and disease.