{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T17:24:04Z","timestamp":1790616244609,"version":"4.1.0"},"reference-count":54,"publisher":"Public Library of Science (PLoS)","issue":"10","license":[{"start":{"date-parts":[[2020,10,8]],"date-time":"2020-10-08T00:00:00Z","timestamp":1602115200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"DOI":"10.1371\/journal.pone.0240290","type":"journal-article","created":{"date-parts":[[2020,10,8]],"date-time":"2020-10-08T17:54:03Z","timestamp":1602179643000},"page":"e0240290","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":19,"title":["Emergence of highly pathogenic H5N2 and H7N1 influenza A viruses from low pathogenic precursors by serial passage in ovo"],"prefix":"10.1371","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2363-1548","authenticated-orcid":true,"given":"Agnes Tinuke","family":"Laleye","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3044-465X","authenticated-orcid":true,"given":"Celia","family":"Abolnik","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2020,10,8]]},"reference":[{"issue":"1","key":"pone.0240290.ref001","doi-asserted-by":"crossref","first-page":"3","DOI":"10.3201\/eid1201.051024","article-title":"H5N1 outbreaks and enzootic influenza","volume":"12","author":"RG Webster","year":"2006","journal-title":"Emerg Infect Dis"},{"issue":"2","key":"pone.0240290.ref002","doi-asserted-by":"crossref","first-page":"1146","DOI":"10.1128\/JVI.73.2.1146-1155.1999","article-title":"The surface glycoproteins of H5 influenza viruses isolated from humans, chickens, and wild aquatic birds have distinguishable properties","volume":"73","author":"M Matrosovich","year":"1999","journal-title":"J Virol"},{"issue":"1","key":"pone.0240290.ref003","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1128\/JVI.19.1.54-60.1976","article-title":"Attenuation of pathogenicity of fowl plague virus by recombination with other influenza A viruses nonpathogenic for fowl: nonexclusive dependence of pathogenicity on hemagglutinin and neuraminidase of the virus","volume":"19","author":"R Rott","year":"1976","journal-title":"J Virol"},{"issue":"1","key":"pone.0240290.ref004","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/0042-6822(77)90059-9","article-title":"Correlation of pathogenicity and gene constellation of an influenza A virus (fowl plague). I. Exchange of a single gene","volume":"81","author":"C Scholtissek","year":"1977","journal-title":"Virology"},{"key":"pone.0240290.ref005","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1146\/annurev.bi.56.070187.002053","article-title":"The structure and function of the hemagglutinin membrane glycoprotein of influenza virus","volume":"56","author":"DC Wiley","year":"1987","journal-title":"Annu Rev Biochem"},{"issue":"1","key":"pone.0240290.ref006","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1016\/0042-6822(92)90775-K","article-title":"Hemagglutinin activation of pathogenic avian influenza viruses of serotype H7 requires the protease recognition motif R-X-K\/R-R","volume":"188","author":"M Vey","year":"1992","journal-title":"Virology"},{"issue":"7","key":"pone.0240290.ref007","doi-asserted-by":"crossref","first-page":"2407","DOI":"10.1002\/j.1460-2075.1992.tb05305.x","article-title":"Influenza virus hemagglutinin with multibasic cleavage site is activated by furin, a subtilisin-like endoprotease","volume":"11","author":"A Stieneke-Gr\u00f6ber","year":"1992","journal-title":"EMBO J"},{"key":"pone.0240290.ref008","first-page":"182","article-title":"Occurrence and possible mechanisms of cleavage-site insertions in the avian influenza hemagglutinin gene","volume":"1","author":"M Perdue","year":"2003","journal-title":"Avian diseases"},{"issue":"8","key":"pone.0240290.ref009","doi-asserted-by":"crossref","first-page":"2219","DOI":"10.1007\/s00705-017-3337-x","article-title":"Evolution of H5 highly pathogenic avian influenza: sequence data indicate stepwise changes in the cleavage site","volume":"162","author":"C Abolnik","year":"2017","journal-title":"Arch Virol"},{"issue":"1","key":"pone.0240290.ref010","first-page":"e02298","article-title":"Genetic predisposition to acquire a polybasic cleavage site for highly pathogenic avian influenza virus hemagglutinin","volume":"8","author":"N Nao","year":"2017","journal-title":"mBio"},{"issue":"4","key":"pone.0240290.ref011","doi-asserted-by":"crossref","first-page":"693","DOI":"10.3201\/eid1004.030396","article-title":"Recombination resulting in virulence shift in avian influenza outbreak, Chile","volume":"10","author":"DL Suarez","year":"2004","journal-title":"Emerg Infect Dis"},{"issue":"3","key":"pone.0240290.ref012","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1099\/vir.0.80478-0","article-title":"Intersegmental recombination between the haemagglutinin and matrix genes was responsible for the emergence of a highly pathogenic H7N3 avian influenza virus in British Columbia","volume":"86","author":"J Pasick","year":"2005","journal-title":"J Gen Virol"},{"key":"pone.0240290.ref013","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1186\/1743-422X-10-139","article-title":"The highly pathogenic H7N3 avian influenza strain from July 2012 in Mexico acquired an extended cleavage site through recombination with host 28S rRNA","volume":"10","author":"S Maurer-Stroh","year":"2013","journal-title":"Virol J"},{"key":"pone.0240290.ref014","unstructured":"Seekings AH. Emergence of H7 highly pathogenic avian influenza virus from low pathogenicity avian influenza virus. Ph.D Thesis, The Imperial College of London. 2017. Available from: https:\/\/spiral.imperial.ac.uk\/handle\/10044\/1\/52910"},{"key":"pone.0240290.ref015","unstructured":"World Organisation for Animal Health (OIE). Avian influenza (infection with avian influenza viruses) 2015. Available from: https:\/\/www.oie.int\/fileadmin\/Home\/eng\/Health_standards\/tahm\/3.03.04_AI.pdf"},{"issue":"1","key":"pone.0240290.ref016","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1006\/viro.1995.1405","article-title":"Egg fluids and cells of the chorioallantoic membrane of embryonated chicken eggs can select different variants of influenza A (H3N2) viruses","volume":"211","author":"CT Hardy","year":"1995","journal-title":"Virology"},{"issue":"9","key":"pone.0240290.ref017","doi-asserted-by":"crossref","first-page":"2155","DOI":"10.1099\/0022-1317-69-9-2155","article-title":"Multiplication of influenza A viruses with cleavable and non-cleavable haemagglutinin in chicken embryo membranes or organs, and cell cultures derived therefrom","volume":"69","author":"C Scholtissek","year":"1988","journal-title":"J Gen Virol"},{"issue":"2","key":"pone.0240290.ref018","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1007\/BF01317323","article-title":"Cleavability of hemagglutinin determines spread of avian influenza viruses in the chorioallantoic membrane of chicken embryo","volume":"65","author":"R Rott","year":"1980","journal-title":"Arch Virol"},{"issue":"1","key":"pone.0240290.ref019","doi-asserted-by":"crossref","first-page":"755","DOI":"10.1016\/S0042-6822(95)80004-2","article-title":"Molecular changes in virulent mutants arising from avirulent avian influenza viruses during replication in 14-day-old embryonated eggs","volume":"206","author":"T Horimoto","year":"1995","journal-title":"Virology"},{"issue":"1","key":"pone.0240290.ref020","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1007\/BF00370003","article-title":"An Arg-Lys insertion at the hemagglutinin cleavage site of an H5N2 avian influenza isolate","volume":"12","author":"ML Perdue","year":"1996","journal-title":"Virus Genes"},{"key":"pone.0240290.ref021","first-page":"171","article-title":"Pathogenicity shifts in experimental avian influenza virus infections in chickens","volume":"1","author":"DE Swayne","year":"2003","journal-title":"Avian Diseases"},{"issue":"1S","key":"pone.0240290.ref022","first-page":"260","article-title":"Assessing potential pathogenicity of avian influenza virus: current and experimental system","volume":"51","author":"CW Lee","year":"2007","journal-title":"Avian Dis"},{"issue":"2","key":"pone.0240290.ref023","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/0168-1702(90)90018-7","article-title":"Effects of chicken embryo age on time to death following infection by avian influenza viruses: implications for distinguishing highly pathogenic isolates","volume":"16","author":"ML Perdue","year":"1990","journal-title":"Virus Res"},{"issue":"1","key":"pone.0240290.ref024","first-page":"43","article-title":"S. Studies upon the possibilities of avian influenza viruses\u2019 cultivation in chick embryos at different age","volume":"9","author":"I Zarkov","year":"2006","journal-title":"Bulgarian Journal of Veterinary Medicine"},{"issue":"2","key":"pone.0240290.ref025","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1292\/jvms.60.273","article-title":"A possible mechanism for selection of virulent avian influenza A viruses in 14-day-old embryonated eggs","volume":"60","author":"T Horimoto","year":"1998","journal-title":"J Vet Med Sci"},{"key":"pone.0240290.ref026","first-page":"166","article-title":"Recovery of minority subpopulations of highly pathogenic avian influenza virus","volume":"47","author":"M Brugh","year":"2003","journal-title":"Avian Diseases"},{"key":"pone.0240290.ref027","unstructured":"Manvell RJ, Horner R, Akol G, Abolnik C, Romito M, Brown IH. Isolation of an influenza A virus subtype H5N2 from ostriches in South Africa in 2004. In Proceedings of the 3rd International Ratite Science Symposium of the WPSA, Madrid, October 2005 (pp. 14\u201316)."},{"issue":"2","key":"pone.0240290.ref028","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1111\/j.1750-2659.2009.00074.x","article-title":"Characterisation of a highly pathogenic influenza A virus of subtype H5N2 isolated from ostriches in South Africa in 2004","volume":"3","author":"C Abolnik","year":"2009","journal-title":"Influenza Other Resp. Viruses"},{"issue":"4","key":"pone.0240290.ref029","doi-asserted-by":"crossref","first-page":"865","DOI":"10.1637\/10171-041012-Reg.1","article-title":"Molecular analysis of the 2011 HPAI H5N2 outbreak in ostriches, South Africa","volume":"56","author":"C Abolnik","year":"2012","journal-title":"Avian Dis"},{"issue":"1s","key":"pone.0240290.ref030","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1637\/11110-042815-Reg","article-title":"Susceptibility and status of avian influenza in ostriches","volume":"60","author":"C Abolnik","year":"2016","journal-title":"Avian Dis"},{"key":"pone.0240290.ref031","first-page":"493","article-title":"A simple method of estimating fifty percent endpoints","volume":"27","author":"LJ Reed","year":"1938","journal-title":"Am. J. Hygiene"},{"issue":"3S","key":"pone.0240290.ref032","doi-asserted-by":"crossref","first-page":"1079","DOI":"10.1637\/0005-2086-47.s3.1079","article-title":"Development of real-time RT-PCR for the detection of avian influenza virus","volume":"47","author":"E Spackman","year":"2003","journal-title":"Avian Dis"},{"key":"pone.0240290.ref033","first-page":"95","article-title":"BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95\/98\/NT","volume":"41","author":"TA Hall","year":"1999","journal-title":"Nucl. Acids. Symp. Ser"},{"issue":"4","key":"pone.0240290.ref034","doi-asserted-by":"crossref","first-page":"1160","DOI":"10.1093\/bib\/bbx108","article-title":"MAFFT online service: multiple sequence alignment, interactive sequence choice and visualization","volume":"20","author":"K Katoh","year":"2019","journal-title":"Brief Bioinform"},{"issue":"6","key":"pone.0240290.ref035","doi-asserted-by":"crossref","first-page":"739","DOI":"10.1007\/s11262-019-01700-z","article-title":"Inventory of molecular markers affecting biological characteristics of avian influenza A viruses","volume":"55","author":"A Suttie","year":"2019","journal-title":"Virus Genes"},{"key":"pone.0240290.ref036","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1186\/s12866-015-0465-x","article-title":"A complete map of potential pathogenicity markers of avian influenza virus subtype H5 predicted from 11 expressed proteins","volume":"15","author":"Z Khaliq","year":"2015","journal-title":"BMC Microbiol"},{"key":"pone.0240290.ref037","unstructured":"Richard M, Fouchier R, Monne I. Mechanisms and risk factors for mutation from low to highly pathogenic avian influenza virus. External Report, European Food Safety Authority. 2017."},{"issue":"8","key":"pone.0240290.ref038","doi-asserted-by":"crossref","first-page":"4375","DOI":"10.1128\/JVI.03181-13","article-title":"Emergence of a highly pathogenic avian influenza virus from a low-pathogenic progenitor","volume":"88","author":"I Monne","year":"2014","journal-title":"Journal of virology"},{"issue":"1","key":"pone.0240290.ref039","doi-asserted-by":"crossref","first-page":"1324","DOI":"10.1080\/22221751.2019.1663131","article-title":"Mutations in the H7 HA and PB1 genes of avian influenza a viruses increase viral pathogenicity and contact transmission in guinea pigs","volume":"8","author":"C Dreier","year":"2019","journal-title":"Emerg Microbes Infect"},{"key":"pone.0240290.ref040","unstructured":"National Center for Biotechnology Information (NCBI), 2020. Basic local alignment search tool (BLAST) accessible at https:\/\/blast.ncbi.nlm.nih.gov\/Blast.cgi."},{"issue":"1\u20132","key":"pone.0240290.ref041","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.vetmic.2010.05.037","article-title":"Genetic characterization and susceptibility on poultry and mammal of H7N6 subtype avian influenza virus isolated in Japan in 2009","volume":"147","author":"Y Uchida","year":"2011","journal-title":"Vet Microbiol"},{"issue":"1","key":"pone.0240290.ref042","doi-asserted-by":"crossref","first-page":"400","DOI":"10.1128\/JVI.02082-15","article-title":"A Unique Multibasic Proteolytic Cleavage Site and Three Mutations in the HA2 Domain Confer High Virulence of H7N1 Avian Influenza Virus in Chickens","volume":"90","author":"el-SM Abdelwhab","year":"2015","journal-title":"J Virol"},{"issue":"6","key":"pone.0240290.ref043","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1002\/rmv.1846","article-title":"Molecular Pathogenesis of H5 Highly Pathogenic Avian Influenza: The Role of the Haemagglutinin Cleavage Site Motif","volume":"25","author":"JM Luczo","year":"2015","journal-title":"Rev Med Virol"},{"issue":"29\u201330","key":"pone.0240290.ref044","doi-asserted-by":"crossref","first-page":"3580","DOI":"10.1016\/j.vaccine.2008.05.001","article-title":"Characterization of influenza virus variants with different sizes of the non-structural (NS) genes and their potential as a live influenza vaccine in poultry","volume":"26","author":"L Wang","year":"2008","journal-title":"Vaccine"},{"key":"pone.0240290.ref045","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1016\/j.cmi.2017.10.013","article-title":"Next-generation sequencing technologies and their application to the study and control of bacterial infections","volume":"24","author":"J Besser","year":"2018","journal-title":"Clin Microbiol Infect"},{"issue":"1\u20132","key":"pone.0240290.ref046","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/S0378-1135(00)00168-1","article-title":"Structural features of the avian influenza virus hemagglutinin that influence virulence","volume":"74","author":"ML Perdue","year":"2000","journal-title":"Vet Microbiol"},{"issue":"8","key":"pone.0240290.ref047","doi-asserted-by":"crossref","first-page":"1358","DOI":"10.3390\/v3081358","article-title":"Homologous recombination in negative sense RNA viruses","volume":"3","author":"GZ Han","year":"2011","journal-title":"Viruses"},{"issue":"6229","key":"pone.0240290.ref048","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1038\/340156a0","article-title":"Increased viral pathogenicity after insertion of a 28S ribosomal RNA sequence into the haemagglutinin gene of an influenza virus","volume":"340","author":"D Khatchikian","year":"1989","journal-title":"Nature"},{"issue":"1","key":"pone.0240290.ref049","doi-asserted-by":"crossref","first-page":"462","DOI":"10.1006\/viro.1994.1555","article-title":"Nonhomologous recombination between the hemagglutinin gene and the nucleoprotein gene of an influenza virus","volume":"204","author":"M Orlich","year":"1994","journal-title":"Virology"},{"issue":"5","key":"pone.0240290.ref050","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1007\/s007050170128","article-title":"Changes in the haemagglutinin and the neuraminidase genes prior to the emergence of highly pathogenic H7N1 avian influenza viruses in Italy","volume":"146","author":"J Banks","year":"2001","journal-title":"Arch Virol"},{"key":"pone.0240290.ref051","article-title":"Emergence and selection of a highly pathogenic avian influenza H7N3 virus","author":"N Beerens","year":"2020","journal-title":"J Virol"},{"issue":"1","key":"pone.0240290.ref052","doi-asserted-by":"crossref","first-page":"349","DOI":"10.20506\/rst.28.1.1875","article-title":"Avian influenza: the Canadian experience","volume":"28","author":"J Pasick","year":"2009","journal-title":"Rev. Sci. Tech. Off. Int. Epiz"},{"issue":"9","key":"pone.0240290.ref053","doi-asserted-by":"crossref","first-page":"1531","DOI":"10.3201\/eid1909.130087","article-title":"Highly pathogenic avian influenza A(H7N3) virus in poultry workers, Mexico, 2012","volume":"19","author":"I Lopez-Martinez","year":"2013","journal-title":"Emerg Infect Dis"},{"issue":"1","key":"pone.0240290.ref054","doi-asserted-by":"crossref","first-page":"11518","DOI":"10.1038\/s41598-018-29944-z","article-title":"Evolution of high pathogenicity of H5 avian influenza virus: haemagglutinin cleavage site selection of reverse-genetics mutants during passage in chickens","volume":"8","author":"JM Luczo","year":"2018","journal-title":"Sci Rep"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0240290","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,10,8]],"date-time":"2020-10-08T17:55:54Z","timestamp":1602179754000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0240290"}},"subtitle":[],"editor":[{"given":"Camille","family":"Lebarbenchon","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2020,10,8]]},"references-count":54,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2020,10,8]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0240290","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,10,8]]}}}