Genome-wide Association Studies for Immune Response and Resilience to Aleutian Disease in Mink

Abstract Background Aleutian disease (AD), caused by the Aleutian mink disease virus, is a significant health concern for mink, resulting in substantial economic losses for the mink industry. Although phenotypic selection of AD-resilient mink based on immune response and/or indicator traits is practiced by some mink farms, the genetic architecture of immune response and resilience to AD has not been widely explored. Thus, the objective of this study was to conduct the first genome-wide association studies (GWAS) analyses to identify genomic regions and genes associated with immune response and feed-intake-related resilience to AD in mink. Methods The genotypes and phenotypes, including two immune response traits measured by antigen-based enzyme-linked immunosorbent assay (ELISA-G) and iodine agglutination test (IAT) and two feed-intake-related resilience traits measured by the daily variation in feed intake (Varf) and proportion of off-feed days (DOF), of 1,411 mink from an AD-positive farm was used in this study. The de-regressed breeding values were derived from the estimated breeding values for each trait and utilized as pseudo-phenotypes in the analyses. Results A total of 17, eight, and seven significant (false-discovery-rate-adjusted-p-value (q) <0.01) single nucleotide polymorphisms (SNP) were detected to be associated with ELISA-G, IAT, and DOF, respectively, but no significant SNP was detected for Varf. A total of 141 genes were annotated from the significant SNPs for ELISA-G, and three of them, MPIG6B, RUNX2, and C4A, might have important roles in immune-mediated responses to AD. Two (TNFRSF11Aand C4A) of the 44 genes annotated in IAT were found to be involved in the immune system process. In addition, 42 genes were annotated in DOF, and two of them, ADCY7 and CNDP2, were related to feed intake or appetite. A total of five significant (q<0.05) overrepresented gene ontology enrichment terms, which play important roles in the adaptive immune response or complement system, were detected for ELISA-G. Conclusions The significant SNPs and genes detected in this study help provide a better understanding of the genetic architecture underlying the immune response and resilience of mink to AD and the potential for improving the resilience of mink to AD using marker-assisted/genomic selection.