Kidneys of some of rZH501-M847-A-infected mice and the mice infected with the mixture of rZH501-M847-G and rZH501-M847-A showed pyknotic cells in glomeruli on day 3 p.i (Fig.  S2B ). Most of the infected mice had viral antigens in the smooth muscle of interlobular and arcuate arteries from day 2 p.i., and in the mesangium of glomeruli on days 3 and 4 p.i (Fig. S2C, D) . Although no pathology was detected in the kidneys of the ZH501- Five-week-old, female CD-1 mice were inoculated i.p. with 10 5 PFU of ZH501, rZH501-M847-A, rZH501-M847-G or a mixture of rZH501-M847-A and rZH501-M847-G. At 1 through 7 days p.i., serum, liver, spleen, kidney and brain were collected from infected mice, and virus titers were individually determined by plaque assay. Two to sixteen mice were used for each time point. In some cases, samples were collected from dead mice. They were: ZH501-infected mice-2 at day 3 p.i., 1 at 5 day p.i. and 1 at day 6 p.i.; rZH501-M847-G-infected mice-1 at day 7 p.i.; rZH501-M847-A-infected mice-2 at days 2 and 4 p.i., 5 at day 3 p.i., 3 at day 5 p.i., and 4 at day 6 p.i.; and rZH501-M847-G/rZH501-M847-A-co-infected mice-8 at day 3 p.i., 7 at day 6 p.i., and 2 at day 6 p.i. doi:10.1371/journal.pone.0009986.g004 infected mice, viral antigens were detected from day 3 in the mesangium of glomeruli and in the smooth muscle of interlobular and arcuate arteries from days 3 to 7 p.i. The kidneys of rZH501-M847-G-infected mice showed no pathology. Some of the infected mice exhibited viral antigens from days 5 to 7 day p.i. in the smooth muscle of interlobular and arcuate arteries (Fig. S2H) , whereas no viral antigens were detected in the glomeruli (Fig.  S2G ).