TABLE 1.

Plaque sizes of E mutants at different temperatures

Virus	Mutation(s)	Plaque size (mm)a at:
		33°C	37°C	39°C
Alb154 (mutant 3)	E protein K63A, K67A; gene 4 tag	0.5	0.9	0.9
Alb183 (mutant 4)	E protein D60A, R61A, K63A; gene 4 tag	0.5	0.9	0.9
Alb129	Gene 4 tag	0.6	2.8	3.0
Wild type	None	0.7	2.9	3.0
Alb4	N protein Δ380–408	0.5	1.0	0.5

^aPlaque diameters were measured at 48 h after infection of L2 cell monolayers. Each value is the average from 20 plaques.