Table 2.

Positively selected sites in neuraminidase from viruses from different clusters

Dataset	Description	Number of sequences	Length of alignment (bp)	Number of sites under positive selection		Positively selected sites1
				SLAC	FEL	SLAC	FEL
2.1	Avian strains	137	1368	0	0
2.2	North American swine strains	171	1368	3	7	46TG, 396B,453T	46TG,53T,75,127,285,339B,453T
2.3	Eurasian swine strains	92	1368	0	1		75
2.4	Seasonal human strains	1735	1371	5	6	84,151,222,275A,382	84,151,275A,344B,365BG,382
2.5	Pandemic 2009 human strains	1397	1368	0	2		35,453T

¹In this column, B indicates that the site lies in the B-cell antigenic regions [21]. G means that it is a potential glycosylation site. T indicates that the site lies in the T-cell antigenic regions [19]. We start numbering from the amino acids MNPN. A means that the site is associated with drug-resistance [7].