Influence of rAAV serotype and route of administration on sex-mediated discordance in rAAV transgene expression. (A) Stable hFIX expression 6 weeks after tail vein infusion of 1 × 10¹¹ rAAV-5 CAGG-FIX, in a cohort (n = 3) of male and female B6.CB17-Prkdc-SzJ mice. Error bars indicate SEM. (B) Genomic DNA was extracted from liver, spleen, lungs, and kidney from male (M) and female (F) mice 6 weeks after tail vein administration of 1 × 10¹¹ rAAV-5 CAGG-FIX. Genomic DNA (0.5 μg) was used for PCR amplification using transgene-specific primers designed to amplify a 521-bp product. Proviral copy number was deduced from standards, which consisted of serial dilutions of vector DNA (1.5 × 10^–3 to 1.5 copies) in 0.5 μg control genomic DNA. Integrity of DNA was determined by amplifying a 604-bp region of murine β-actin gene and is shown at the bottom of the panel.