Figure 4.

(a) Production of the viral vector in 293FT cells transfected with pSD31-siRNA, pSD31-siRNA(O), pSD31-siRNA(O’) and pSD31-siRNA(O2) respectively, namely, the response to unilateral reduction in the level of antisense RNA (i), in response to that of sense RNA (iii), in response to reversal these parameter (ii and iv), and in response to simultaneous reductions in levels of both sense and antisense RNA (v). The vector stocks were diluted 1000- and 3000-fold for tittering. (b) The effect of regular expression (+) and an ∼20% reduction (−) in the level of the sense or the antisense RNA or both on production of the viral vector. The vector titers shown are derived from results of an experiment that was conducted in triplicate for each sample.