Table 2. Molecular characterizations of the H5N1 viruses on HA, PB2, NA, M2 and PB1-F2.

Virusesa	Collection date	HA (H3 numbering)						PB2			NA		M2		PB1-F2
		Connecting peptide	110	158	160	224–228	318	591	627	701	274b	Stalk deletion	27	31	58–90 truncated
A/Alberta/01/2014c	2014.1.3	RERRRKR/G	H	D	A	NRQSG	T	Q	E	D	H	49–68	I	S	Yes
A/tiger/Jiangsu/01/2013c	2013.1.20	RERRRKR/G	H	D	A	NGQSG	T	Q	E	D	H	49–68	I	S	Yes
Ws/HN/SMX1/2015	2015.1.4	RERRRKR/G	H	D	A	NGQSG	T	Q	E	D	H	49–68	I	S	Yes
Ws/HN/SMX3/2015	2015.1.4	RERRRKR/G	H	D	A	NGQSG	T	Q	E	D	H	49–68	I	S	Yes
Ws/HN/SMX4/2015	2015.1.5	RERRRKR/G	H	D	A	NGQSG	T	Q	E	D	H	49–68	I	S	Yes
Ws/HN/SMX9/2015	2015.1.5	RERRRKR/G	H	D	A	NGQSG	T	Q	E	D	H	49–68	I	S	Yes
Po/HN/SMX1/2015	2015.1.5	RERRRKR/G	H	D	A	NGQSG	T	Q	E	D	H	49–68	I	S	Yes
En/HN/SMX1/2015	2015.1.5	RERRRKR/G	H	D	A	NGQSG	T	Q	E	D	H	49–68	I	S	Yes

^aWs: whooper swan; Po: pochard; En: environment; HN: Henan.

^bN2 numbering.

^cThe sequences of the reference strains are downloaded from GISAID and GenBank databases.