Table 2.

The positions of adaptive amino acid substitutions in different host-pair calculations.

	Avian–canine (H3N2)	Equine–canine (H3N8)	Avian–equine (H3N8)	Avian–human (H3N2)	Avian–swine (H3N2)	Swine–human (H3N2)
PB2	82,195,334,365,511,570	107,221,292	/	9,44,67,81,82,120,194, 199,227,271,353,382, 456,463,475,526,567, 569,627,682,697	271,456,591,645	120,199,353,475,526, 567,569,627,674,682
PB1	108,361,397,469,517,723, 744	/	61,157,164,175,261, 429,587,642	212,327,336,361,486,576, 581,586,587,619,709,741	336,339,433,486, 581,741	576,586,619,709
PB1-F2	13	/	10,38,51,52,68,69,74	76	76	8,18,20,62
PA	208,234,243,277,369,432, 441,615	27,256,675	55,57,99,118,216,217, 244,277,336,437,683, 689	28,55,57,62,65,66,225,268, 311,332,383,385,552, 557,573,668	254,362	311,573
HA	10,45,81,111,128,172, 196,222,232,261,326, 435,489,496	29,54,83,118, 222,328,483	25,56,63,70,81,83,88, 102,111,121,122,143,146, 160,182,207,244,252, 278,300,304,309,328, 331,347,355,387,442, 464,479,489,541	31,33,48,53,75,172, 186,192,196,198,202, 212,223,225,227, 361,384,452,489,530	/	33
NP	125,159,374,418,428,473	375	41,50,117,146,245,293, 305,312,319,345,351,374, 453,496,498	16,18,31,61,65,100,131, 197,214,280,283,286,293, 305,312,313,343,344,357, 422,423,442,455,459,472	21,119,189,190, 289,305,357,400, 425,444,456	18,52,65,131,214,239, 280,283,286,312, 344,372,406,422,442, 455,459
NA	9,24,54,65,156,208,372, 380,432	62,147	19,22,43,47,82,91,93,160, 199,211,233,250,258, 260,266,301,311,319, 321,339,359,374, 386,393,415,454	18,23,42,152,217,223, 247,249,312,369,374, 389,404,439	/	152,217,247,249,312, 389
M1	/	/	85	115,121,137,174,218,239	116,209,214	115,137,167,174, 218,230,239
M2	/	/	50	54,57,78,86,93	77	57,78,86,89,93
NS1	75,172,230	/	96,156,186,214	41,82,125,135,144,196,	125,189	28,82,135,144,196
NS2	/	/	33,35	57,107	32,34,57	107

The position of signature shared in CIVs was shown in bold. /, no host-specific amino acid substitutions in the protein.