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Aggregation of Single Nucleotide Polymorphisms in a Human H5N1 Clade 2.2 Hemagglutinin
Provedor de dados: 17
Autores: Henry L. Niman; Magdi D. Saad; Jeffery Tjaden; Kenneth C. Earhart; Marshall R. Monteville; Mona M. Aly; Moustafa M. Mansour; Nasr El-Sayed; Ahmed E. Nayel; Ahmed S. Abdelghani; Hala M. Esmat; Emad M. Labib; Ehab A. Ayoub; Abdelattar Arafa; Gregory A. Raczniak; Mensah Agyen-Frempong; William K. Ampofo; Bruce R. Boynton.
The rapid evolution of the H5N1 serotype of avian influenza has been explained by a mechanism involving the selection of single nucleotide polymorphisms generated by copy errors.  The recent emergence of H5N1 Clade 2.2 in fifty countries, offered a unique opportunity to view the acquisition of new polymorphism in these evolving genomes.  We analyzed the H5N1 hemagglutinin gene from a fatal human case from Nigeria in 2007.  The newly emerged polymorphisms were present in diverse H5N1 isolates from the previous year.  The aggregation of these polymorphisms from clade 2.2 sub-clades was not supported by recent random mutations, and was most easily explained by recombination between closely related sequences.
Tipo: Manuscript
Palavras-chave: Genetics &amp; Genomics; Evolutionary Biology.
Ano: 2007
URL: http://precedings.nature.com/documents/743/version/2

Concurrent Acquisition of a Single Nucleotide Polymorphism in Diverse Influenza H5N1 Clade 2.2 Sub-clades
Provedor de dados: 17
Autores: Henry L. Niman; Magdi D. Saad; Mona M. Aly; Jeffery  Tjaden; Kenneth C. Earhart; Marshall R. Monteville; Moustafa M. Mansour; Nasr El-Sayed; Ahmed E. Nayel; Ahmed S. Abdelghani; Hala M. Esmat; Emad M. Labib; Ehab A. Ayoub; Abdelattar  Arafa; Gregory A. Raczniak; Mensah Agyen-Frempong; William K. Ampofo; Bruce R. Boynton.
Highly pathogenic Influenza A H5N1 was first identified in Guangdong Province in 1996, followed by human cases in Hong Kong in 1997. The number of confirmed human cases now exceeds 300, and the associated Case Fatality Rate exceeds 60%. The genetic diversity of the serotype continues to increase. Four distinct clades or sub-clades have been linked to human cases. The gradual genetic changes identified in the sub-clades have been attributed to copy errors by viral encoded polymerases that lack an editing function, thereby resulting in antigenic drift. We report here the concurrent acquisition of the same polymorphism by multiple, genetically distinct, clade 2.2 sub-clades in Egypt, Russia, and Ghana. These changes are not easily explained by the current...
Tipo: Manuscript
Palavras-chave: Biotechnology; Chemistry; Ecology; Genetics &amp; Genomics; Immunology; Microbiology; Bioinformatics.
Ano: 2007
URL: http://precedings.nature.com/documents/459/version/3

Aggregation of Single Nucleotide Polymorphisms in a Human H5N1 Clade 2.2 Hemagglutinin
Provedor de dados: 17
Autores: Henry L. Niman; Magdi D. Saad; Jeffery Tjaden; Kenneth C. Earhart; Marshall R. Monteville; Mona M. Aly; Moustafa M. Mansour; Nasr El-Sayed; Ahmed E. Nayel; Ahmed S. Abdelghani; Hala M. Esmat; Emad M. Labib; Ehab A. Ayoub; Abdelattar Arafa; Gregory A. Raczniak; Mensah Agyen-Frempong; William K. Ampofo; Bruce R. Boynton.
The evolution of H5N1 has attracted significant interest 1-4 due to linkages with avian 5,6 and human infections 7,8.  The basic tenets of influenza genetics 9 attribute genetic drift to replication errors caused by a polymerase complex that lacks a proof reading function.  However, recent analysis 10 of swine influenza genes identifies regions copied with absolute fidelity for more than 25 years.  In addition, polymorphism tracing of clade 2.2 H5N1 single nucleotide polymorphisms identify concurrent acquisition 11 of the same polymorphism onto multiple genetic backgrounds in widely dispersed geographical locations.  Here we show the aggregation of regional clade 2.2 polymorphisms from Germany, Egypt, and sub-Sahara Africa onto a human Nigerian H5N1...
Tipo: Manuscript
Palavras-chave: Biotechnology; Ecology; Genetics &amp; Genomics; Immunology; Microbiology; Bioinformatics.
Ano: 2007
URL: http://precedings.nature.com/documents/743/version/1