Diversity of interferon inducible Mx gene in horses and association of variations with susceptibility vis-à-vis resistance against equine influenza infection.
Equine influenza (EI) is primarily an infection of the upper respiratory tract and is one of the major infectious respiratory diseases of economic importance in equines. Re-emergence of the disease, species jumping by H3N8 virus in canines and possible threat of human pandemic due to the unpredictable nature of the virus have necessitated research on devising strategies for preventing the disease. The myxovirus resistance protein (Mx) has been reported to confer resistance to Orthomyxo virus infection by modifying cellular functions needed along the viral replication pathway. Polymorphisms and differential antiviral activities of Mx gene have been reported in pigs and chicken. Here we report the diversity of Mx gene, its expression in response to stimulation with interferon (IFN) α/β and their association with EI resistance and susceptibility in Marwari horses. Blood samples were collected from horses declared positive for equine influenza and in contact animals with a history of no clinical signs. Mx gene was amplified by reverse transcription from total RNA isolated from peripheral blood mononuclear cells (PBMCs) stimulated with IFN α/β using gene specific primers. The amplified gene products from representative samples were cloned and sequenced. Nucleotide sequences and deduced amino acid sequences were analyzed. Out of a total 24 amino acids substitutions sorting intolerant from tolerant (SIFT) analysis predicted 13 substitutions with functional consequences. Five substitutions (V67A, W123L, E346Y, N347Y, S689N) were observed only in resistant animals. Evolutionary distances based on nucleotide sequences with in equines ranged between 0.3-2.0% and 20-24% with other species. On phylogenetic analysis all equine sequences clustered together while other species formed separate clades.
['Manuja|Balvinder K|BK|', 'Manuja|Anju|A|', 'Dahiya|Rajni|R|', 'Singh|Sandeep|S|', 'Sharma|R C|RC|', 'Gahlot|S K|SK|']
D000595:Amino Acid Sequence D019943:Amino Acid Substitution D000818:Animals D019143:Evolution, Molecular D020022:Genetic Predisposition to Disease D014644:Genetic Variation D006734:Horse Diseases D006736:Horses D053123:Influenza A Virus, H3N8 Subtype D008969:Molecular Sequence Data D009154:Mutation D064547:Myxovirus Resistance Proteins D009976:Orthomyxoviridae Infections D010802:Phylogeny D016415:Sequence Alignment
Mx gene Susceptibility Resistance Equine influenza