Biomaterial Database

The evolution of the type I interferon gene family in mammals. 1995

A L Hughes

Department of Biology, Pennsylvania State University, University Park 16802, USA.

A phylogenetic analysis of mammalian type I interferon (IFN) genes showed: (1) that the three main subfamilies of these genes in mammals (IFN-beta, IFN-alpha, and IFN-omega) diverged after the divergence of birds and mammals but before radiation of the eutherian orders and (2) that IFN-beta diverged first. Although apparent cases of interlocus recombination among mouse IFN-alpha genes were identified, the hypothesis that coding regions of IFN-alpha genes have been homogenized within species by interlocus recombination was not supported. Flanking regions as well as coding regions of IFN-alpha were more similar within human and mouse than between these species; and reconstruction of the pattern of nucleotide substitution in IFN-alpha coding regions of four mammalian species by the maximum parsimony method suggested that parallel substitutions have occurred far more frequently between species than within species. Therefore, it seems likely that IFN-alpha genes have duplicated independently within different eutherian orders. In general, type I IFN genes are subject to purifying selection, which in the case of IFN-alpha and IFN-beta is strongest in the putative receptor-binding domains. However, analysis of the pattern of nucleotide substitution among IFN-omega genes suggested that positive Darwinian selection may have acted in some cases to diversify members of this subfamily at the amino acid level.

UI	MeSH Term	Description	Entries
D007370	Interferon Type I	Interferon secreted by leukocytes, fibroblasts, or lymphoblasts in response to viruses or interferon inducers other than mitogens, antigens, or allo-antigens. They include alpha- and beta-interferons (INTERFERON-ALPHA and INTERFERON-BETA).	Interferons Type I,Type I Interferon,Type I Interferons,Interferon, Type I,Interferons, Type I
D008322	Mammals	Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.	Mammalia,Mammal
D008957	Models, Genetic	Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Genetic Models,Genetic Model,Model, Genetic
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
D011995	Recombination, Genetic	Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.	Genetic Recombination,Recombination,Genetic Recombinations,Recombinations,Recombinations, Genetic
D005810	Multigene Family	A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)	Gene Clusters,Genes, Reiterated,Cluster, Gene,Clusters, Gene,Families, Multigene,Family, Multigene,Gene Cluster,Gene, Reiterated,Multigene Families,Reiterated Gene,Reiterated Genes
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
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012689	Sequence Homology, Nucleic Acid	The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.	Base Sequence Homology,Homologous Sequences, Nucleic Acid,Homologs, Nucleic Acid Sequence,Homology, Base Sequence,Homology, Nucleic Acid Sequence,Nucleic Acid Sequence Homologs,Nucleic Acid Sequence Homology,Sequence Homology, Base,Base Sequence Homologies,Homologies, Base Sequence,Sequence Homologies, Base