Transgenics

Abstract

With the explosion of genetic information becoming available in large part due to the Human Genome Project, there is a need to determine the function and role of previously unknown genes. Much can be learned from the comparison of the sequences of these new genes to those of previously characterized genes, and from computer modeling to infer the structure of specific gene products. In vitro assay systems can also often provide information on the function of gene products. These assays, as well as cell culture systems, have the advantage of being relatively high throughput and low cost. However, these systems lack the complexity of the whole organism. The inability to study the interaction of different organs and/or cell types limits the information that can be derived from these technologies. In vivo experiments, while more costly, can provide information that the above-mentioned systems cannot approach, due to the fact that they provide the metabolic, physiologic and pathologic complexity absent in these other systems. Transgenic technology can be thought of as two individual technologies, gene addition and gene modification (Tab. 1), which allow researchers to perform genetic engineering to investigate the roles of specific genes during development and in various disease states. Gene addition often involves the overexpression of genes, while gene targeting is most often used to create null mutations or “knock outs”. Characterizing and studying the resulting animals can often contribute great insights into the role that individual genes may play in normal physiology and in various disease states. In addition, this technology provides the potential to create new in vivo disease and metabolic models.