TABLE 2.

Growth of T1L × D-EA3 reassortant viruses in the presence and absence of E64

Virus strain	Origin of gene segmenta:										Viral titer inb:		L+E64/L ratioc	Rankd
	L1	L2	L3	M1	M2	M3	S1	S2	S3	S4	E64-treated cells	Untreated cells
Parental
T1L	L	L	L	L	L	L	L	L	L	L	4.18 × 105	2.20 × 107	0.0190
D-EA3	E	E	E	E	E	E	E	E	E	E	1.25 × 107	6.93 × 107	0.181
Reassortant
3-45	E	E	L	E	E	E	L	E	E	E	1.08 × 105	6.50 × 105	0.165	1
3-40	E	E	E	E	E	E	L	E	L	E	7.80 × 105	4.75 × 106	0.164	2
3-35	E	E	L	L	E	L	L	E	E	E	1.20 × 106	7.70 × 106	0.156	3
3-28	E	L	E	E	E	E	E	E	E	E	1.63 × 106	1.73 × 107	0.0946	4
3-25	E	E	E	E	E	E	L	E	E	E	3.60 × 106	4.55 × 107	0.0790	5
3-2	L	E	L	E	E	E	L	E	E	E	3.20 × 106	5.05 × 107	0.0634	6
3-32	E	E	L	E	E	E	L	E	E	E	1.25 × 106	3.30 × 107	0.0379	7
3-46	E	E	L	E	E	L	L	L	L	E	1.34 × 105	6.88 × 106	0.0194	8
3-37	L	E	L	L	E	L	L	E	E	L	2.22 × 106	1.31 × 108	0.0169	9
3-9	L	E	L	E	L	L	L	E	E	L	2.30 × 105	1.95 × 107	0.0118	10
3-7	E	E	E	E	E	E	E	E	E	L	2.25 × 105	4.50 × 107	0.00500	11

^aParental origin of each gene segment: L, gene segment derived from T1L; E, gene segment derived from D-EA3. 

^bL cells (4 × 10⁵) were infected with virus strains at an MOI of 2 PFU per cell. After a 1-h adsorption period, the inoculum was removed, fresh medium with or without 100 μM E64 was added, and cells were incubated at 37°C for 24 h. Cells were frozen and thawed twice, and viral titers in cell lysates were determined by plaque assay. The results are presented as mean viral titer at 24 h for two to four independent experiments for the reassortant viruses and six independent experiments for the parental viruses. 

^cThe mean viral titer at 24 h in E64-treated cells was divided by that in untreated cells to calculate an L+E64/L ratio for each virus strain. 

^dReassortant viruses are ranked from highest to lowest based on their L+E64/L ratios.