Fitness and major histocompatibility complex variation in bottlenose dolphins (#162)
An individual’s fitness is determined by traits such as mate choice, reproductive output, resistance to parasites and survival to old age. The search for the genetic basis of fitness variation has until recently often relied on neutral genetic markers, including mitochondrial DNA and microsatellites. However, ecological and evolutionary processes relevant to fitness can only be inferred by non-neutral genes such as those of the major histocompatibility complex (MHC). MHC variants, including ‘supertypes’ (i.e. clusters of MHC variants which encode peptides that interact with particular types of antigens) influence many important biological traits in vertebrates. MHC variation has previously been associated with direct and indirect fitness traits, and has been shown to play an important role in mating. In this study we investigated the potential relationship between MHC variation and fitness traits in two populations of bottlenose dolphins (Tursiops cf. aduncus) in Western Australia. We used conventional Sanger and Illumina MiSeq next-gen sequencing methods to infer MHC sequence variants and supertypes. MHC variation was compared to mate choice, reproductive success, male alliance formation and survival to old age in hundreds of dolphins. We will present our findings, linking MHC variation with fitness traits, with an emphasis on the behavioural traits of mate choice and reproductive success.