TABLE 2.

Summary of properties of variant viruses

Gene order	Relative plaque sizea	Relative burst sizeb	LD50c	Onset of symptomsd
P M G (wild type)	1.00	1.00	14	6.0
G M P	0.64	0.23	21	4.5
M G P	1.03	1.07	21	5.5
P G M	0.80	0.21	12	5.5
G P M	0.66	0.016	30	5.5
M P G	1.13	0.51	11	5.5

^aMeasured at 30 h postinfection (see Table 1). 

^bMeasured at 17 h postinfection (see Fig. 5). 

^cPFU per mouse inoculated intranasally. 

^dDays after intranasal inoculation of 100 PFU per mouse (see Fig. 6).