How the interaction between host organisms and their gut microbiota promotes rapid adaptation to trophic niches in threespine stickleback
Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
Final Report Abstract
Gut-associated microbial communities, or gut microbiota, significantly impact many aspects of their host’s biology, including nutrient metabolism and immune system regulation. Despite these effects, gut microbiota composition varies greatly both within and among host species. Although we recognize the vast microbial diversity across host organisms, we still lack comprehensive knowledge on how ecological, morphological, and genetic factors shape gut microbiota composition and how these variations affect host fitness. Understanding this variation is crucial for revealing how microbes can influence host adaptation to new ecological niches. Combining field surveys with controlled experiments can help identify the factors driving gut microbiota composition and its impact on host ecology and, thus, their evolutionary trajectories. This project aimed to explore how various aspects of the biology of threespine stickleback fish (Gasterosteus aculeatus; hereafter referred to as stickleback) interact with environmental factors to create patterns of gut microbiota variation within and among populations and how this variation influences host specialization to different trophic niches. We also used a controlled pond experiment to assess whether gut microbiota composition and diversity correlate with stickleback growth rate, a proxy for host fitness. Additionally, a laboratory experiment evaluated gut microbiota plasticity, or the ability to restructure the microbiota in response to a new diet. Threespine stickleback are ideal for studying eco-evolutionary dynamics as they exhibit profound ecological and evolutionary parallelism across independent populations, are amenable for experiments conducted under naturalistic and laboratory conditions and show substantial phenotypic and genetic variation within and among populations. Beyond this system, we examined the predictability of gut microbiota changes using a novel quantitative approach and discussed current knowledge on the biogeographic distribution of microbial communities. Identifying the factors structuring gut microbiota helps predict how hosts, their microbiota, and the environment interact during animal hosts’ adaptation to different ecological niches, enhancing our understanding of host-associated microbial diversity and its eco-evolutionary implications.
Publications
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Congress of the European Society for Evolutionary Biology, Prague, Czech Republic, 2022: Threespine stickleback gut microbiota divergence associated with repeated shifts in trophic ecology
Härer, Andreas
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Quantifying (non)parallelism of gut microbial community change using multivariate vector analysis. Ecology and Evolution, 12(12).
Härer, Andreas & Rennison, Diana J.
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A positive association between gut microbiota diversity and vertebrate host performance in a field experiment.
Härer, Andreas; Thompson, Ken A.; Schluter, Dolph & Rennison, Diana J.
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Assessing the validity of fecal sampling for characterizing variation in threespine stickleback’s gut microbiota. PLOS ONE, 18(9), e0290875.
Härer, Andreas & Rennison, Diana J.
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Conference of The American Society of Naturalists, Monterey, USA, 2023: Host fitness is associated with gut microbiota diversity and composition in threespine stickleback
Härer, Andreas
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Gut microbiota parallelism and divergence associated with colonisation of novel habitats. Molecular Ecology, 32(20), 5661-5672.
Härer, Andreas; Mauro, Alexander A.; Laurentino, Telma G.; Rosenblum, Erica B. & Rennison, Diana J.
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The biogeography of host‐associated bacterial microbiomes: Revisiting classic biodiversity patterns. Global Ecology and Biogeography, 32(6), 931-944.
Härer, Andreas & Rennison, Diana J.
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The effects of host ecology and phylogeny on gut microbiota (non)parallelism across birds and mammals. mSphere, 8(6).
Härer, Andreas & Rennison, Diana J.
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Virtual Evolution, 2023: A positive association between gut microbiota diversity and vertebrate host fitness in a field experiment
Härer, Andreas
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3rd Joint Congress on Evolutionary Biology, Montreal, Canada, 2024: Contrasting biogeography of host-associated and free-living microbial metacommunities across two study systems
Härer, Andreas
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Gut Microbiota Uniqueness Is Associated with Lake Size, a Proxy for Diet Diversity, in Stickleback Fish. The American Naturalist, 203(2), 284-291.
Härer, Andreas & Rennison, Diana J.
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Host ecotype and rearing environment are the main drivers of threespine stickleback gut microbiota diversity in a naturalistic experiment. Royal Society Open Science, 11(6).
Härer, Andreas; Frazier, Christine J. & Rennison, Diana J.
