Screening for associations of horse immune gene polymorphisms to EAV infection

KALEMKERIAN P.B.; FRANCISCO E.I.; METZ G.E.; PERAL GARCIA P.; GIOVAMBATTISTA G.; ECHEVERRIA M.G.; DIAZ S.

Edimburgo

Congreso; XXXII Conference of the International Society for Animal Genetics; 2010

International Society for Animal Genetics

Equine Viral Arteritis (EVA) is a systemic infection in equids with variable outcome, ranging from subclinical infections to severe disease, and also has the capacity to induce abortion in pregnant mares. Persistent infections in stallions play a major epidemiological role in the dissemination and perpetuation of EAV. The disease is caused by a virus of the Arteviridae family. In 2001, as the result of an outbreak in Argentina, the virus was isolated from semen samples for the fi rst time in South America. The aim of this study was to investigate polymorphisms in two immune response related genes (ELA-DRA, TNF-á) and three microsatellite loci (UM011, TKY08, LEX52) located within or near the ELA in order to identify associations with susceptibility to EVA infection. Silla Argentino (N=168) horse samples were serologically tested to EAV by the virus neutralization method during 2002, 2004 and 2006. Genotyping was performed by Pyrosequencing three SNPs on TNF-á promoter and ELA-DRA second exon, and STR genotyping was performed in automated DNA sequencer. Allelic and genotypic frequencies, heterozygozity, number of alleles and Linkage disequilibrium (LD) were estimated. All markers showed polymorphism. LD was confi rmed between ELA-DRA and TNF-á (p<0.01). Association analysis in108 EAV-infected and 60 EAV-non-infected horses did not show signifi cant differences in the allele or genotypic frequencies between infected and non-infected horses. No association could be established between the serological condition and the studied polymorphisms. However, some genotypic and haplotypic combinations showed differences in the incidence between infected and non-infected groups.