M.cinxia-Microbiota

The microbiota within the gut of the Glanville fritillary butterfly was efficiently altered by antibiotic treatment, and restored either by fecal transplants or self-resilience after antibiotic relaxation. The dominant species of the gut bacterial community of the larvae did not impact larval performances and metabolism, but rather significantly impacted the host immunity by up-regulating the expression of a gene involved in the response against pathogens. Our study is consistent with the growing literature suggesting that Lepidoptera may not have a gut microbiota beneficial to larval growth or survival, however it showed that other traits which might be important for the fitness of the individuals in nature might have been disregarded while characterizing this host-microbe interaction. To our knowledge, this work is the first one to strongly suggest a link between the gut environment and the immune system of the Glanville fritillary butterfly, a model organism for eco-evolutionary biology.