Knowledgeoftheevolutionofpathogensisofgreatmedicalandbiologicalsignificancetotheprevention,diagnosis,andtherapyofinfectiousdiseases.InordertounderstandtheoriginandevolutionoftheSARS-CoV(severeacuterespiratorysyndrome-associatedcoronavirus),wecollectedcompletegenomesequencesofallvirusesavailableinGenBank,andmadecomparativeanalyseswiththeSARSCoV.GenomicsignatureanalysisdemonstratesthatthecoronavirusesalltaketheTGTTastheirrichesttetranucleotideexcepttheSARS-CoV.Adetailedanalysisoftheforty-twocompleteSARS-CoVgenomesequencesrevealedtheexistenceoftwodistinctgenotypes,andshowedthattheseisolatescouldbeclassifiedintofourgroups.OurmanualanalysisoftheBLASTNresultsdemonstratesthattheHE(hemagglutinin-esterase)geneexistsintheSARS-CoV,andmanymutationsmadeitunfamiliartous.
