Titration sensitivity test for MoMLV-based vectors in comparison with HIV-1-based counterparts. (a) Maps of vector constructs used for the test. pSR-CMV-SV-N2A-GFP-polyA, Modified MoMLV vector; pDHIV-101, defective HIV-1-based transfer construct expressing Tat, Rev and Vpu accessory proteins; pHR-cPPT, fully gutted HIV-1-based transfer construct using an internal CMV promoter (CMV Pro) for transgene expression, with eGFP mediated by an internal ribosome entry site element. cPPT, Central polypurine tract; RRE, Rev response element; for other abbreviations, see Fig. 1 legend. (b) Titres in ten cell lines from human and mouse. (c) Transduction efficiency in representative cell lines using concentrated vector. *, 0.01<P≤0.05; ***, P≤0.001.