These observations imply that during persistent infection Ad5 underwent spontaneous mutations by sequence-specific breakage and nonhomologous end-end joining recombination events .
these observations imply that during persistent infection ad5 underwent spontaneous mutations by sequence-specific breakage and nonhomologous end-end joining recombination events .
O O O O O O O B-virus O O O O O O O B-other_name I-other_name I-other_name I-other_name I-other_name O