Genomic Analyses of Aleutian Disease Resilience in American Mink

Abstract

Aleutian disease (AD) causes severe health issues and results in substantial economic losses for the mink industry. The ineffectiveness of vaccination, medication, and culling strategies in controlling AD has compelled mink farmers to select AD-resilient mink. However, as expounded in Chapter 2 of this thesis, the absence of a comprehensive understanding of the genetic/genomic architecture of AD resilience hinders breeders from incorporating this innovative trait into their breeding programs. Thus, this thesis aimed to provide a comprehensive view of the genetic and genomic architecture of AD resilience and explore the potential utilization of genomic information in the selection process for AD resilience. Genetic correlations elucidated in Chapter 3 delineated the genetic relationships among various AD tests and other AD-resilient traits. The outcomes emphasized the antigen-based enzyme-linked immunosorbent assay test as the most reliable and practical indicator trait for selecting AD-resilient mink among all AD tests. Chapter 4 delved into the genetic structure of farmed mink, utilizing phenotypes from the first Axiom Affymetrix Mink 70K single nucleotide polymorphism (SNP) panel. The updated population genomics information from Chapter 4 directed the genomic analyses throughout this thesis. Selection signatures (Chapter 5) and genome-wide association studies (GWAS, Chapter 6) were performed to explore the genomic architecture of AD resilience. The detected SNPs provided an opportunity for improving the resilience of mink to AD using marker-assisted selection or genomic selection in mink, and the identified genes and biological pathways contributed to a deeper understanding of the genomic architecture underlying the immune response and resilience of mink to AD. Chapter 7 examined various genomic prediction methods to assess their feasibility and determine the optimal strategy for leveraging genomic information to augment genetic gains for AD resilience in mink. The most suitable prediction approach was recommended for each AD-resilient trait based on prediction accuracies and biases of different methods for each trait. In conclusion, the studies conducted in this thesis not only offer practical insights and recommendations for the prospective implementation of genetic/genomic selection for AD resilience but also advance our comprehension of the genomic architecture and biological pathways associated with AD resilience in mink.