Chromosomal neo gene correction by AAV vectors, a, Map of the AAV vector genomes used. AAV-SNori is the parent vector containing a functional neo gene. AAV-SNO39 and AAV-SNO648 are identical to AAV-SNori but contain the nt-39 or nt-648 mutations (sequence differences shown), respectively. The locations of the AAV terminal repeats (TR), promoters with transcription start sites (arrows), neo gene, p15A replication origin, polyadenylation site (pA), SalI and fused BamHI-BglII restriction sites, and the probe used in Southern analysis are indicated. b, Southern blot of genomic DNA from untransduced HSNO39 cells and 11 G418-resistant clones of HSNO39 cells transduced with AAV-SNO648, digested with BamHI and probed for neo sequences. The sizes of fragments hybridizing to neo in the parental HSNO39 line are indicated on the left. The positions of size standards are shown on the right. c, Southern analysis as in a but digested with BamHI and SalI. The corrected 2.7-kb fragments are indicated.