RT Journal Article
SR Electronic
T1 Disruption of flour beetle microbiota limits experimentally evolved immune priming response, but not pathogen resistance
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.07.11.499528
DO 10.1101/2022.07.11.499528
A1 Arun Prakash
A1 Deepa Agashe
A1 Imroze Khan
YR 2022
UL http://biorxiv.org/content/early/2022/07/12/2022.07.11.499528.abstract
AB Host-associated microbiota play a fundamental role in the training and induction of different forms of immunity, including inducible as well as constitutive components. However, direct experiments analysing the relative importance of microbiota during evolution of different immune functions are missing. We addressed this gap by using experimentally evolved lines of Tribolium castaneum that either produced inducible immune memory-like responses (immune priming) or constitutively expressed basal resistance (without priming), as mutually exclusive strategies against Bacillus thuringiensis infection. We disrupted the microbial communities in these evolved lines and estimated the impact on the beetle’s ability to mount a priming response vs basal resistance. Populations that had evolved immune priming lost the ability to mount a priming response upon microbiota disruption. Microbiota manipulation also caused a drastic reduction in their reproductive output and post-infection longevity. In contrast, in pathogen-resistant beetles, microbiota manipulation did not affect post-infection survival or reproduction. The divergent evolution of immune responses across beetle lineages was thus associated with divergent reliance on the microbiome. Whether the latter is a direct outcome of differential pathogen exposure during selection or reflects evolved immune functions remains unclear. We hope that our results will motivate further experiments to understand the mechanistic basis of these complex evolutionary associations between microbiota, host immune strategies, and fitness outcomes.Competing Interest StatementThe authors have declared no competing interest.