Transplantation of genetically engineered primary cells for the analysis of gene function in CNS development

Transplantation of genetically engineered primary cells into the CNS allows an analysis of gene function that is often not otherwise possible, such as with germ line mutations that result in embryonic lethality or that have pleiotropic effects. We describe the methods and use of this approach for the analysis of gene function during the development of oligodendrocytes, the myelin-forming cells of the CNS. Primary oligodendrocyte progenitor cells are isolated from the neonatal rat brain, expanded in vitro with mitogens, and genetically altered by the introduction of transgenes. The development and use of an efficient eukaryotic expression vector for optimal DNA-mediated gene transfer in these progenitor cells is detailed. Transplantation of either wild-type or genetically engineered primary cells into normal and myelin-deficient hosts allows an analysis of the effects of gene manipulations on this cell lineage in vivo. The application of these approaches for the analysis of growth factor receptor function during oligodendrocyte development is described.