TABLE 2.

Nucleotide and amino acid differences between the wild-type (WT) H9N2 strain and the mouse-adapted (MA) H9N2 strain.

Segments	Nucleotide sites	WT	MA	Amino acid sites	WT	MA
PB1	2131	A	G	711	I	V
PA	1051	G	A	351	E	K
HA	611	C	A	204	T	K
NP	1131	T	C	377	N	N
NP	1223	T	C	408	V	A
NP	1296	T	C	432	N	N
NA	93	G	A	31	T	T
NA	202	A	G	68	T	A
M	827	T	C	276	F	S