Effect of TNPO3 knockdown on transduction efficiency of MMTV and HIV-1 vectors. (A) Hela cells transfected with the TNPO3-specific or non-silencing siRNA were transduced with HIV-1 and MMTV vectors 48 h after transfection. At 48 h post transduction cells were harvested and the percentage of EGFP-positive cells was determined by flow cytometry. Transduction efficiency in TNPO3-specific siRNA-treated cells relative to control siRNA-treated cells is shown. Results represent mean values ± standard deviation of three independent experiments. (B) The expression levels of TNPO3 at the time of transduction (48 h post transfection) were determined by immunoblotting with an anti-TNPO3-specific antibody. Equivalent loading and blotting was confirmed by membrane re-probing using an anti-actin-specific antibody.