Time course dependence and specificity of the biased productive coinfection events. (A and B) HeLa cells were incubated with the DsRed and/or the GFP reporter HIV-1 on day 1 (A, left, D1) or incubated first with the DsRed reporter virus and/or 24 h later with the GFP reporter virus (A, right, D2). Coinfection indexes calculated from both conditions were plotted (B). (C and D) Same day incubation or coincubation with MLV-DsRed and MLV-GFP or HIV-DsRed and MLV-GFP were conducted and analyzed as for panel A, left. (A and C) Representative results of experiments performed 3 times in duplicate. (B and D) Averages calculated from 3 independent experiments. Two-proportion z test; ***, z > 3.29, P < 0.001; **, z > 2.57, P < 0.01. The error bars indicate standard deviations.