a. AAV integration in the forward orientation gene traps Ube3a-ATS, causing premature transcription termination at the AAV vector-derived polyadenylation sequence element (red box).
b. In the reverse orientation, convergent transcription with the AAV vector-derived Cas9 transcript disrupts Ube3a-ATS.
c. Paternal Ube3a (red line) is similarly disrupted (“silenced”) by convergent transcription.