Effect of androgens on rAAV-mediated transgene expression. (A) Human FIX expression in C57Bl/6 competent mice 6 weeks after tail vein administration of 1 × 10¹¹ rAAV-2 CAGG-FIX vector particles. M indicates naive males (n = 3); CM, castrated animals (n = 5); F, naive females (n = 3). Transgene expression values represent means together with the standard error for each cohort. (B) Stable hFIX levels were determined 10 weeks after tail vein administration of 1 × 10¹¹ rAAV-2 CAGG-FIX vector particles in unmanipulated female mice (F), female mice that had been oophorectomized 2 weeks prior to vector administration (F + O), oophorectomized female mice treated with DHT prior to vector administration (F + T), naive male mice (M), and male mice primed with DHT prior to vector administration (M + T). Human FIX expression values are depicted as average together with the standard error of the mean of each cohort containing between 3 to 7 mice. (C) Southern blot analysis of DNA isolated from murine liver 10 weeks after tail vein administration 1 × 10¹¹ rAAV CAGG-FIX vector particles. DNA samples were digested with NheI to release an internal fragment of 1.5 kb. Sample order from right to left is as follows: lane 1, unmanipulated female mouse (F); lane 2, oophorectomized mouse (F + O); lane 3, oophorectomized mouse treated with DHT (F + T); lane 4, naive male mouse (M); lane 5, male mouse primed with DHT (M + T); lane 6, DNA from a mock-transduced male mouse. Lanes 7 and 8 are control mouse DNA spiked with 4.2 and 0.42 copies per diploid genome of plasmid pAV CAGG-FIX digested with NheI.