Table 1. Amino acid changes associated with neurovirulence in the HN or SH gene.

Gene/Genome	Position ofamino acid	The changes in amino acid	Strain	Genotype orSubgenotype	Effect onneurovirulence	GenBank No.(Reference No.)	Methods
HN	335	lysine→glutamic acid (K→E)	Urabe vaccine	B	Decreased	X93181 [34]FJ375177 [39]FJ375178 [39]	Based on the epidemiological data Based on the rat model
		lysine→glutamic acid (K→E)	Urabe AM9	B	Similarneurotoxicity	[33]	Based on the rat model
		lysine→arginine (K→R)	Lit-976	C2	Decreased	AY502059 [21]	Based on the epidemiological data
		lysine→arginine (K→R)	Odate 1	I	Increased	D86170 [6]	Based on the epidemiological data
	354	proline/glutamine→histidine(P or Q→H)	Kilham	A	Increased	AY502062 [21]	Based on the epidemiological data
	356	Glutamic acid/aspartic acid→serine(E or D→S)	Kilham	A	Increased	AY502062 [21]	Based on the epidemiological data
	360	arginine→cystine (R→C)	The mutant ofKilham (M13)	A	Increased	[18]	Based on the animal model
	464	asparagine→lysine (N→K)	SKB (Urabe AM9)	B	Increased	AF314559 [12]FJ375177 [39]FJ375178 [39]	Based on the epidemiological data Based on the rat model
	466	serine→asparagine (S→N)	88-1961	H	Decreased	[22]	Based on the rat model
SH	29	alanine (A)	Lit1023	C2	Decreased	AY039721 [23]	Based on the epidemiological data
	48	serine (S)	Lit1023	C2	Decreased	AY039721 [23]	Based on the epidemiological data
Genome	at specificgenome sites	Genetic heterogeneity	Urabe AM9	B	Affect forneurovirulence.	[44]	Based on the cell line and the rat model