How does the major histocompatibility complex influence reproductive success in white-tailed deer (Odocoileus virginianus)?

Abstract

Major histocompatibility complex (MHC) gene products can influence sexual selection through their impact on the vertebrate immune system. Individuals with greater MHC diversity are generally believed to have more effective immune systems, thereby allowing these individuals to allocate more resources towards growth and reproduction. However, maximum MHC diversity may be too costly for the individual, suggesting that maximum diversity is not always optimal. This research examined how MHC diversity, measured as pairwise allelic distances between two unlinked MHC type II loci (exon 2 for the classical antigen-binding protein MHC-DRB, exon 2 for the accessory protein MHC-DOB) influenced morphology (Chapter 2), annual reproductive success (Chapter 3), and pre- and post-copulatory selection (Chapter 4) in an enclosed white-tailed deer (Odocoileus virginianus) population in Alabama. To generate these allelic distances, we first sequenced the second exons of MHC-DRB and MHC-DOB on the MiSeq platform (Chapter 1). Since studies conducted with domestic ruminants found a unique MHC II gene structure in which MHC-DRB and MHC-DOB were separated by a recombination hotspot due to an ancestral chromosomal inversion, we also assessed the degree of linkage between these loci in white-tailed deer.