Advanced transgenic and gene-targeting approaches

Over the past two decades the techniques associated with the manipulation o f the mouse genome have provided a powerful approach toward the better unde rstanding of gene function. Conventional transgenic and gene targeting appr oaches have been used extensively, and these techniques have been particula rly rewarding for neuroscientists. Nevertheless, the traditional approaches toward genome manipulation have certain limitations that diminish their us efulness for studying more sophisticated biological processes. Therefore, V ariations to these techniques have recently been developed. The improvement s are focused on two areas: one provides regulated control of transgene exp ression using an inducible expression system; and the other provides the op portunity to inactivate genes in specific cells and at predetermined develo pmental stages with a conditional gene targeting system. This review summar izes the advantages as well as some of the technical difficulties of these new approaches. The application of these advanced approaches in biomedical research, particularly neuroscience, are also discussed.