Biomaterial Database

Evidence for recombination in the envelope gene of maedi-visna virus. 2003

Valgerdur Andrésdóttir

Institute for Experimental Pathology, University of Iceland, Keldur, IS-112 Reykjavík, Iceland. valand@hi.is

Frequent recombination occurs during replication in all retroviruses examined. This increases the genetic variation in the retroviral population and may be of importance in the evolution of the virus. Maedi-visna virus (MVV), a retrovirus of sheep, has a highly variable envelope gene. In a previous experiment, 20 sheep were infected with an uncloned strain of MVV and virus was isolated at regular intervals for 7 years. We sequenced the envelope genes of a number of these strains and found evidence for recombination that may have contributed to the observed high frequency of antigenic variants.

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
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
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
D000940	Antigenic Variation	Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)	Antigen Switching,Antigenic Diversity,Variation, Antigenic,Antigen Variation,Antigenic Switching,Antigenic Variability,Switching, Antigenic,Diversity, Antigenic,Switching, Antigen,Variability, Antigenic,Variation, Antigen
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
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli
D014759	Viral Envelope Proteins	Integral membrane proteins that are incorporated into the VIRAL ENVELOPE. They are glycosylated during VIRAL ASSEMBLY.	Envelope Proteins, Viral,Viral Envelope Glycoproteins,Viral Envelope Protein,Virus Envelope Protein,Virus Peplomer Proteins,Bovine Leukemia Virus Glycoprotein gp51,Hepatitis Virus (MHV) Glycoprotein E2,LaCrosse Virus Envelope Glycoprotein G1,Simian Sarcoma Virus Glycoprotein 70,Viral Envelope Glycoprotein gPr90 (Murine Leukemia Virus),Viral Envelope Glycoprotein gp55 (Friend Virus),Viral Envelope Proteins E1,Viral Envelope Proteins E2,Viral Envelope Proteins gp52,Viral Envelope Proteins gp70,Virus Envelope Proteins,Envelope Glycoproteins, Viral,Envelope Protein, Viral,Envelope Protein, Virus,Envelope Proteins, Virus,Glycoproteins, Viral Envelope,Peplomer Proteins, Virus,Protein, Viral Envelope,Protein, Virus Envelope,Proteins, Viral Envelope,Proteins, Virus Envelope,Proteins, Virus Peplomer
D014790	Visna-maedi virus	A species of LENTIVIRUS, subgenus ovine-caprine lentiviruses (LENTIVIRUSES, OVINE-CAPRINE), that can cause chronic pneumonia (maedi), mastitis, arthritis, and encephalomyelitis (visna) in sheep. Maedi is a progressive pneumonia of sheep which is similar to but not the same as jaagsiekte (PULMONARY ADENOMATOSIS, OVINE). Visna is a demyelinating leukoencephalomyelitis of sheep which is similar to but not the same as SCRAPIE.	Maedi Virus,Maedi-Visna Virus,Visna Virus,Maedi Viruses,Maedi Visna Virus,Visna Maedi Virus
D015752	Genes, env	DNA sequences that form the coding region for the viral envelope (env) proteins in retroviruses. The env genes contain a cis-acting RNA target sequence for the rev protein (	HIV rev-Responsive Element,env Genes,rev-Responsive Element,env Gene,Element, HIV rev-Responsive,Element, rev-Responsive,Elements, HIV rev-Responsive,Elements, rev-Responsive,Gene, env,HIV rev Responsive Element,HIV rev-Responsive Elements,rev Responsive Element,rev-Responsive Element, HIV,rev-Responsive Elements,rev-Responsive Elements, HIV
D016133	Polymerase Chain Reaction	In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.	Anchored PCR,Inverse PCR,Nested PCR,PCR,Anchored Polymerase Chain Reaction,Inverse Polymerase Chain Reaction,Nested Polymerase Chain Reaction,PCR, Anchored,PCR, Inverse,PCR, Nested,Polymerase Chain Reactions,Reaction, Polymerase Chain,Reactions, Polymerase Chain