ABSTRACT
This chapter reviews aspects of viral biology essential for engineering vectors, highlight landmark studies using viruses to overcome traditional limitations in gene editing, and outline important considerations for the use of viral vectors in new systems or for new targets. DNA viruses are assessed as replicon vectors for efficient gene editing through homology-directed repair (HDR). The chapter then reviews RNA viruses as mobile vectors for gene-editing reagent delivery. The initial report of gene editing using RNA viruses was significant because it demonstrated editing in a plant by an RNA viral vector that expresses all the reagents required for gene editing. Negative-sense RNA viruses could provide a larger carrying capacity than the positive-sense RNA viruses, as the authors of this study demonstrated expression of both the sgRNA and Cas9 from the virus and editing at the infiltrated site. RNA viral vectors are rapidly emerging as effective means for delivering genome engineering reagents.
