TABLE 4.
Rate of nonsynonymous substitutions of H6N1, H9N2, and H5N1 influenza viruses that circulate in Hong Kong
| Gene | Nucleotide range analyzede | Substitution rate (10−3/site/yr) ± SE for:
|
Pf for:
|
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Reference virus Tl/HK/W312/97 (H6N1) versus
|
Reference virus Qa/HK/G1/97 (H9N2) versus H9N2 viruses of 1999c | Reference virus Ck/HK/258/97 (H5N1) versus H5N1 viruses of 1997d | H6(I):H9 | H6(I):H5 | H6(II):H9 | H6(II):H5 | H5:H9 | |||
| H6N1 viruses of 1999 (I)a | H6N1 viruses of 2000 (II)b | |||||||||
| PB2 | 988–2289 | 1.8 ± 1.5 | 0.8 ± 0.7 | 1.8 ± 0.3 | 4.3 ± 1.5 | NS | <0.05 | <0.05 | <0.05 | <0.05 |
| PB1 | 67–1428 | 1.8 ± 0.3 | 1.0 ± 0.5 | 0.8 ± 0.4 | 4.8 ± 1.7 | <0.05 | <0.05 | NS | <0.05 | <0.05 |
| PA | 25–1677 | 1.4 ± 0.4 | 1.1 ± 0.2 | 1.3 ± 0.2 | 4.6 ± 1.7 | NS | <0.05 | NS | <0.05 | <0.05 |
| HA | 4.4 ± 1.4 | 2.9 ± 0.7 | 4.6 ± 0.9 | 4.2 ± 0.7 | NS | NS | <0.05 | <0.05 | NS | |
| NP | 46–1398 | 1.1 ± 0.9 | 0.4 ± 0.6 | 1.6 ± 0.5 | 2.7 ± 1.2 | NS | <0.05 | <0.05 | <0.05 | <0.05 |
| NA | 6.0 ± 1.3 | 5.2 ± 0.4 | 2.0 ± 0.2 | 4.6 ± 0.6 | NS | NS | <0.05 | NS | <0.05 | |
| M1 | 50–784 | 0.0 | 0.0 | 0.7 ± 0.7 | 3.0 ± 1.9 | <0.05 | <0.05 | <0.05 | <0.05 | <0.05 |
| NS1 | 39–719 | 7.0 ± 5.2 | 3.6 ± 3.3 | 0.2 ± 0.5 | 8.8 ± 2.6 | <0.05 | NS | <0.05 | <0.05 | <0.05 |
Reference virus compared to group I H6N1 viruses Ph/HK/SH39/99, Qa/HK/172120/99, and Qa/HK/172130/99.
Reference virus compared to group II H6N1 viruses Ph/HK/NT261/00, Qa/HK/SF550/00, Qa/HK/SF595/00, and Cu/HK/FY295/00.
Reference virus compared to H9N2 viruses Qa/HK/A17/99, Pg/HK/FY6/99, Ck/HK/NT16/99, Qa/HK/SSP10/99, and Ph/HK/SSP11/99.
Reference virus compared to H5N1 viruses Dk/HK/Y283/97, Dk/HK/P46/97, Gs/HK/W355/97, Ck/HK/786/97, and Ck/HK/915/97.
HA gene nucleotide ranges analyzed H5, 18 to 1046; H6, 29 to 1063; H9, 87 to 1076; NA gene nucleotide ranges analyzed: N1, 66 to 1373; N2, 20 to 1415.
Calculated for comparing the rates of nonsynonymous substitutions between different groups. H6(I):H9, H6N1 viruses of 1999 compared to H9N2 viruses; H6(I):H5, H6N1 viruses of 1999 compared to H5N1 viruses; H6(II):H9, H6N1 viruses of 2000 compared to H9N2 viruses; H6(II):H5, H6N1 viruses of 2000 compared to H5N1 viruses; H5:H9, H5N1 viruses compared to H9N2 viruses. If P was <0.05, there was a significant difference between the compared groups. If P was >0.05, there was no significant difference (NS) between the compared groups.