Determining if early mRNA & protein levels correlate with reduced replication in F1-R, a sendai virus variant

Sendai virus (SeV) causes a respiratory infection in rodents while a Z strain variant, F1-R, causes a systemic infection. RGV0, a Fushimi strain variant containing F1-R's F and M, but not P or L gene mutations, also causes a systemic infection. In replication studies, F1-R produces fewer viruses than either wild-type (wt) SeV or RGV0. We hypothesized that F1-R's reduced virus production is due to L and/or P gene mutations. To test this, real time RT-PCR and Western blot analysis were used to compare, over time, viral mRNA and protein production of F1-R, RGV0 and their respective parental wt strains. Significant expression differences were detected between RGV0 and its parental wt strain, between the wt strains, and between RGV0 and F1-R. The results suggest that strain differences rather than F1-R's L and/or P gene mutations are responsible F1-R's reduced virus production as compared to RGV0