The concept of phenotypic plasticity, or the ability of a single genotype to produce varying phenotypes depending on the environment, is a central focus of biology. However, animals are not a "single genome" in that they also maintain intimate associations with complex communities of microbes. It has been proposed that the genomes of hosts and associated microbes should be combined into a wholistic "holobiont" and "hologenome", upon which natural selection acts. Yet, our knowledge of how the microbiome contributes to host plasticity remains poorly understood. We are working to address this critical gap by experimentally determining how the microbiome and rodent host species interactively influence animals' physiological responses to variation in diet. Using comparative and experimental approaches (including microbiome transplants), we will test for whether gut microbial communities contribute to phenotypic traits and differential host phenotypic plasticity.
Two perspective articles that cover this topic are: -- Kohl, K.D., Carey, H.V. (2016) A place for host-microbe symbiosis in the comparative physiologist’s toolbox. Journal of Experimental Biology. 219: 3496-3504. [Link][PDF] -- Kohl, K.D. (2018) A microbial perspective on the ‘Grand Challenges in Comparative Animal Physiology’. mSystems. 3: e00146-17. [Link][PDF]