The effects of host genetic architecture on the gut microbiome
composition of Chinook salmon (Oncorhynchus tshawytscha)
The microbiome community consists of microbes living in or on an
organism and has been implicated in both host health and function.
Environmental and host-related drivers of the microbiome have been
studied in many fish species, but the role of the host genetic
architecture across populations and among-families within a population
is not well characterized. Here, Chinook salmon (Oncorhynchus
tshawytscha) were used to determine inter-population differences and
additive genetic variation within populations for gut microbiome
diversity and composition. Specifically, hybrid stocks of Chinook salmon
were created by crossing males from eight populations with eggs from an
inbred line of self-fertilized hermaphrodite salmon. Based on
high-throughput sequencing of the 16S rRNA gene, significant gut
microbiome community diversity and composition differences were found
among the hybrid stocks. These differences likely reflect divergent
selection shaping the gut microbiome and its co-evolution with the host.
Furthermore, additive genetic variance components varied among hybrid
stocks, indicative of population-specific heritability patterns,
suggesting the potential to select for specific gut microbiome
composition for aquaculture purposes. Determining the role of host
genetics in shaping their gut microbiome has important implications for
predicting population responses to environmental changes and will thus
impact conservation efforts for declining populations of Chinook salmon.