ABSTRACT
Many different animal viruses have been exploited as vectors, mostly for foreign gene expression in cultured cells but also for gene transfer in vivo. Novel strategies involving site-specific recombination and transposition have also been used to generate recombinant viruses. The large genome size and unusual replication strategy represent major obstacles to the design and construction of expression vectors. The wild-type genome has two genes, one encoding viral replicase and the other encoding a self-cleaving polyprotein containing all the capsid structural proteins. The adenovirus fiber proteins have the ability to disrupt the endosome, releasing the naked capsid into the cytoplasm where it is transported to the nuclear membrane. The transfection of recombinant RNA into cells is unsuitable for certain experiments, especially for gene delivery in vivo. The chapter concludes with a short discussion about the potential of combining certain features of different viruses to make them more suitable vectors.
