A novel 2 bp deletion variant in Ovine-DRB1 gene is associated with increased Visna/maedi susceptibility in Turkish sheep

Abstract

Visna/maedi (VM) is a multisystemic lentivirus infection of sheep that affecting sheep industry across the globe. TMEM154 gene has been identified to be a major VM-associated host gene, nevertheless, a recent study showed that the frequency of the VM-resistant TMEM154 haplotypes was very low or absent in indigenous sheep. Thus, the present study was designed to determine other possible co-receptors associated with VM. For this purpose, DRB1 gene, which is renowned for its role in host immune response against various diseases was targeted. A total number of 151 case–control matched pairs were constructed from 2266 serologically tested sheep. A broad range of DRB1 haplotype diversity was detected by sequence-based genotyping. Moreover, a novel 2 bp deletion (del) in the DRB1 intron 1 was identified. For the final statistic, the sheep carrying VM-resistant TMEM154 diplotypes were removed and a McNemar’s test with a matched pairs experimental design was conducted. Consequently, it was identified for the first time that the 2 bp del variant is a genetic risk factor for VM (p value 0.002; chi-square 8.31; odds ratio 2.9; statistical power 0.90) in the dominant model. Thus, negative selection for 2 bp del variant could decrease VM infection risk in Turkish sheep.

Alternative Molecular Tools for the Fight against Infectious Diseases of Small Ruminants: Native Sicilian Sheep Breeds and Maedi-Visna Genetic Susceptibility

“…Different candidate loci have been previously reported to be involved in MV infection with various levels of statistical significance [15][16][17][18]; however, a genome-wide association study in North American sheep identified a single, major gene (transmembrane protein 154 gene, TMEM154) significantly associated with host vulnerability to MV illness [19].…”

Exploring genetic diversity and variation of Ovar-DRB1 gene in Sudan Desert Sheep using targeted next-generation sequencing

“…Allelic polymorphisms within Ovar-DRB1 affect antigen-MHC II binding, influencing the specificity and efficiency of immune responses [ 40 , 41 ]. Specific Ovar-DRB1 alleles have been linked to differential resistance or susceptibility to diseases in sheep populations [ 42 , 43 ], demonstrating the direct link between genetic diversity and immune response efficacy. The identification of breed-specific allelic diversity in the Ovar-DRB1 gene among SDS breeds holds significant implications for disease resilience and adaptation.…”

Individual Genomic Loci and mRNA Levels of Immune Biomarkers Associated with Pneumonia Susceptibility in Baladi Goats

“…However, the candidate gene method was utilized to evaluate ruminant susceptibility to pneumonia. For example, in sheep, a link between MHC-DRB1 genotypes for mycoplasma ovipneumonia resistance or susceptibility has been documented [ 25 , 43 ]. Additionally, it has been established that progressive pneumonia virus susceptibility is affected by the effects of ovine TMEM154 gene polymorphisms after normal exposure [ 26 ].…”