Gene targeting with recombinant adenoviral vectors

A nonfunctional mutant of a reporter gene (W in the figure) is introduced or is present in a cell (a). In the recombinant targeting vector (b), the viral genes are replaced by a sequence that is homologous to the chromosomal locus targeted for modification. Usually, the modification is introduced between stretches of homology called 5' and 3' homology arms. Z designates an inactivating mutation in the viral repair template. This recombinant adeno-associated virus (rAAV) is used to transduce the cells. Recombination with the chromosomal target (c) can result in repair of the defect and recovery of a healthy cell (d). The frequency of gene targeting is determined as the fraction of infected cells that expresses a functional reporter. Stable integration is confirmed by antibiotic selection and Southern analysis. (In the figure, crosses [X] mark regions of homology between the chromosomal and viral DNA, and ITR indicates an inverted terminal repeat.)