InordertorevealvariationandrevolutionofNPgenesofhumanavianH_5N_1influenzavirusstrains,theNPgeneofahumanavianH_5N_1influenzavirusstraininGuangdongwassequencedandtheglobalNPgenesofstrainswereretrieved.ThesequenceswereanalyzedbyDNAStar5.0,andtheevolu-tionaryspeedwasstudiedwithreferencetotheepidemiologicaldata.ItwasfoundthatNPgenesof45strainsduring1997-2006werehomologicallyclassifiedintothreegroups:strainsin1997-1998,strainsin2004-2005andstrainsfrom2003to2006.Therewere35substitutionsinNPsinallstrainsaccountingforaratioof7.03%(35/498).Anadditionalglycoproteindomain(NGT_(430-432))wasfoundinNPgenesinthestrainsof2003-2006,themutationofN_(370)SinGD-01-06resultedinoccurrenceofonemoreglyco-proteindomain(NES_(368-370)).Inthesynonymousvariation,K_svaluesinNPwere2.03×10~(-5)-2.55×10~(-5)Nt/dandK_avaluesinNPwere1.58×10(-6)-3.10×10~(-6)Nt/d.Theredidn′texistobviouslyselectivepres-sure.Anadditionalglycoproteindomainineverystrainof2003-2006andonemoreinstrainGD-01-06mightchangetheantigenicityofhumanavianH_6N_1influenzavirus.ThevariationonhumanavianH_5N_1influenzastrainsoccurredfrequentlyinthenaturalworld,whichwouldresultinhighprobabilityofhu-man-humantransmissionalongwiththenaturalevolutionofthevirus.
