Host-genotype dependent gut microbiota drives zooplankton tolerance to toxic cyanobacteria

Emilie Macke,Ellen Decaestecker,Luc De Meester,Martijn Callens

doi:10.1038/s41467-017-01714-x

Emilie Macke, Ellen Decaestecker + Show 2 more

Open Access

https://doi.org/10.1038/s41467-017-01714-x

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Journal: Nature Communications	Publication Date: Nov 20, 2017
Citations: 115	License type: open-access

Affiliation: KU Leuven

Abstract

The gut microbiota impacts many aspects of its host’s biology, and is increasingly considered as a key factor mediating performance of host individuals in continuously changing environments. Here we use gut microbiota transplants to show that both host genotype and gut microbiota mediate tolerance to toxic cyanobacteria in the freshwater crustacean Daphnia magna. Interclonal variation in tolerance to cyanobacteria disappears when Daphnia are made germ-free and inoculated with an identical microbial inoculum. Instead, variation in tolerance among recipient Daphnia mirrors that of the microbiota donors. Metagenetic analyses point to host genotype and external microbial source as important determinants of gut microbiota assembly, and reveal strong differences in gut microbiota composition between tolerant and susceptible genotypes. Together, these results show that both environmentally and host genotype-induced variations in gut microbiota structure mediate Daphnia tolerance to toxic cyanobacteria, pointing to the gut microbiota as a driver of adaptation and acclimatization to cyanobacterial harmful algal blooms in zooplankton.

Highlights

The gut microbiota impacts many aspects of its host’s biology, and is increasingly considered as a key factor mediating performance of host individuals in continuously changing environments
To determine the role of gut microbiota in Daphnia tolerance to cyanobacteria, reciprocal gut microbiota transplants were performed among Daphnia genotypes and diet (Fig. 2)
Donor Daphnia from tolerant (T1 and T2) and susceptible (S1 and S2) genotypes were provided with a same inoculum of pond water to ensure a sufficiently diverse gut microbiota, and exposed to either a nontoxic green algal diet or a toxic cyanobacterial diet for 12 generations

Summary

Introduction

The gut microbiota impacts many aspects of its host’s biology, and is increasingly considered as a key factor mediating performance of host individuals in continuously changing environments. Metagenetic analyses point to host genotype and external microbial source as important determinants of gut microbiota assembly, and reveal strong differences in gut microbiota composition between tolerant and susceptible genotypes Together, these results show that both environmentally and host genotype-induced variations in gut microbiota structure mediate Daphnia tolerance to toxic cyanobacteria, pointing to the gut microbiota as a driver of adaptation and acclimatization to cyanobacterial harmful algal blooms in zooplankton. Shapira[9] recently defined the gut microbiota as a multilayered structure, composed of both a flexible pool of microbes that depends on the diversity of the environmental microbial pool and external conditions, and a core microbiota of host-specific microbes that are selectively recruited depending on host genetic factors, most likely mediated by the immune system. Short life cycle, clonal reproduction, and high responsiveness to environmental stressors, combined with the possibility to manipulate its gut microbiota, provide a unique opportunity to study the interplay between host genotype, environment, and microbiota, with a high degree of experimental control[16,17]

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