Particle production and infectivity of PFV-Gag central domain mutants.

<p>(<b>A</b>) Western blot analysis of producer cell lysates (<b>Cell</b>) and pelleted viral supernatants (<b>Virus</b>) with polyclonal antibodies specific for PFV-Gag (α-Gag) and PFV Env-LP (α-Env-LP) or monoclonal antibodies specific for PFV-PR/RT (α-PR/RT) and integrase (α-IN). Residue substitutions in Gag are indicated above each track, (<i>wt</i>) wild type virus, (<i>wt +iRT</i>) wild type virus with defective reverse transcriptase. In the right-hand panel %<i>wt</i> are different <i>wt</i> control loadings and arrows indicate the migration of Gag, Env and Pol proteins. (<b>B</b>) Relative amounts of released Gag quantified from Western blots data from two independent experiments. (<b>C</b>) Relative infectivity of extracellular 293T cell culture supernatants using an eGFP marker gene transfer assay, determined 3 days post infection. Means and standard deviations of three independent experiments are shown. The values obtained using the wild type Gag packaging vector were arbitrarily set to 100%. Absolute titres of these supernatants were 1.8 x 10⁶ to 1.1 x 10⁷ ffu/ml.