Major histocompatibility complex heterozygote advantage and widespread bacterial infections in populations of Chinook salmon (Oncorhynchus tshawytscha)

摘要: Despite growing evidence for parasite-mediated selection on the vertebrate major histocompatibility complex (MHC), little is known about variation in bacterial parasite community within and among host populations or its influence MHC evolution. In this study, we characterize parasitic associated with Chinook salmon (Oncorhynchus tshawytscha) fry five British Columbia (BC), Canada across 2 years, examine whether infections are a potential source of MHC. We found an unprecedented diversity bacteria infecting total 55 unique identified. Bacterial infection rates varied from 9% to 29% there was significant isolation by distance relationship phylogenetic similarity populations. Spatial frequency communities may result differential at Across all populations, heterozygote advantage class II, which be balancing locus. Interestingly, co-inertia analysis indicated only susceptibility associations between few I II alleles specific parasites; no that any provided resistance bacteria. Our results reveal fish underscore importance considering role multiple pathogens evolution adaptations.