Genetic research may result in identifying an immunity or lack thereof to West Nile virus, a Georgia State University professor said during the equine session of the 2007 International Conference on the Status of Plant and Animal Genome Research in San Diego.
Andrey Perelygin was the presenting author of "Characterization of equine innate immunity genes potentially involved in West Nile virus susceptibility." The work arose from Perelygin's previous research on mice.
"Five years ago we discovered a mutation in a mouse," Perelygin said.
West Nile virus is a flavivirus similar to yellow fever. It can induce a variety of manifestations ranging from no symptoms to severe central nervous system damage. Approximately 40 percent of equine West Nile Virus cases result in the death of the horse.
Although West Nile virus did not occur in the United States until 1999, research on flaviviral resistance in mice had been published by 1923. Research published in 1952 indicated that resistance to the yellow fever virus in mice was controlled by a single autosomal dominant allele (a gene contains one allele from each parent. A recessive allele provides the trait only if both alleles of the gene contain that trait while only one dominant allele triggers that allele's trait).
Perelygin's 2002 work focused on an oligodenylate synthase gene. All of the mice carrying a specific allele died of West Nile virus. Subsequent research has also been conducted on mice, as well as one published study involving the CCR5 receptor gene for humans. That CCR5 gene was part of the equine research project as well as three additional receptors, three synthases, and three other genes. Eight of those 10 genes were mapped to individual horse chromosomes, and 54 mutations were identified.
Perelygin's equine project involved grants from the Morris Animal Foundation, the Center for Disease Control, and the Southeastern Center for Emerging Biological Threats. Funding considerations will determine Perelygin's future research projects.
"It's very problematic now to get funding, because funding is very low now," he said.