Biomaterial Database

Evolutionary pathways of the PA genes of influenza A viruses. 1989

K Okazaki, and Y Kawaoka, and R G Webster

Department of Virology and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.

Nucleotide sequences of the PA genes of influenza A viruses, isolated from a variety of host species, were analyzed to determine the evolutionary pathways of these genes and the host specificity of the genes. Results of maximum parsimony analysis of the nucleotide sequences indicate at least five lineages for the PA genes. Those from human strains represent a single lineage, whereas the avian genes appear to have evolved as two lineages--one comprising genes from many kinds of birds (e.g., chickens, turkeys, shorebirds, and ducks) and the other comprising only genes from gulls. H3N2 swine influenza virus PA genes are closely related to the currently circulating duck virus PA gene. By contrast, the H1N1 swine and equine virus PA genes appear to have evolved along independent lineages. Comparison of predicted amino acid sequences disclosed 10 amino acid substitutions in the PA proteins of all avian and H3N2 swine viruses that distinguished them from human viruses. The H1N1 swine viruses seem to be chimeras between human and avian viruses and they contain 8 amino acids not shared by other viruses. The equine viruses also appear to show their own amino acid substitutions. These findings indicate that the PA genes of influenza A viruses have evolved in different pathways defined by apparently unique amino acid substitutions and host specificities. They also indicate that influenza A viruses have been transmitted from avian to mammalian species.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009980	Influenza A virus	The type species of the genus ALPHAINFLUENZAVIRUS that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.	Alphainfluenzavirus influenzae,Avian Orthomyxovirus Type A,FLUAV,Fowl Plague Virus,Human Influenza A Virus,Influenza Virus Type A,Influenza Viruses Type A,Myxovirus influenzae-A hominis,Myxovirus influenzae-A suis,Myxovirus pestis galli,Orthomyxovirus Type A,Orthomyxovirus Type A, Avian,Orthomyxovirus Type A, Human,Orthomyxovirus Type A, Porcine,Pestis galli Myxovirus,Fowl Plague Viruses,Influenza A viruses,Myxovirus influenzae A hominis,Myxovirus influenzae A suis,Myxovirus, Pestis galli,Myxoviruses, Pestis galli,Pestis galli Myxoviruses,Plague Virus, Fowl,Virus, Fowl Plague
D011200	Poultry	Domesticated birds raised for food. It typically includes CHICKENS; TURKEYS, DUCKS; GEESE; and others.	Fowls, Domestic,Domestic Fowl,Domestic Fowls,Fowl, Domestic,Poultries
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004372	Ducks	A water bird in the order Anseriformes (subfamily Anatinae (true ducks)) with a broad blunt bill, short legs, webbed feet, and a waddling gait.	Duck
D005075	Biological Evolution	The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.	Evolution, Biological
D005814	Genes, Viral	The functional hereditary units of VIRUSES.	Viral Genes,Gene, Viral,Viral Gene
D006736	Horses	Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.	Equus caballus,Equus przewalskii,Horse, Domestic,Domestic Horse,Domestic Horses,Horse,Horses, Domestic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein