Effect of using the MVV Env on recovered virus yield of a field-derived LPAI strain. This figure shows the effect of substituting 25% of the viral genes containing plasmids for the MVV envelope gene-containing plasmid on the rescue efficiency of a low pathogenicity avian influenza strain derived from a field sample. The total amount of transfected DNA is 4 μg per well in 6 well plates and 0.8 μg per well in 24 well plates. The average of three replicates is shown and error bars indicate standard deviation. Asterisks indicate levels of statistical significance as follows: *, p < 0.05; **, p < 0.01. wp, well plate.