The red flour beetle Tribolium castaneum: A model for host-microbiome interactions

PLoS One. 2020 Oct 2;15(10):e0239051. doi: 10.1371/journal.pone.0239051. eCollection 2020.

Abstract

A large body of ongoing research focuses on understanding the mechanisms and processes underlying host-microbiome interactions, and predicting their ecological and evolutionary outcomes. To draw general conclusions about such interactions and understand how they are established, we must synthesize information from a diverse set of species. We analysed the microbiome of an important insect model-the red flour beetle Tribolium castaneum-which is a widespread generalist pest of stored cereals. The beetles complete their entire life cycle in flour, which thus serves multiple functions: habitat, food, and a source of microbes. We determined key factors that shape the T. castaneum microbiome, established protocols to manipulate it, and tested its consequences for host fitness. We show that the T. castaneum microbiome is derived from flour-acquired microbes, and varies as a function of (flour) resource and beetle density. Beetles gain multiple fitness benefits from their microbiome, such as higher fecundity, egg survival, and lifespan; and reduced cannibalism. In contrast, the microbiome has a limited effect on development rate, and does not enhance pathogen resistance. Importantly, the benefits are derived only from microbes in the ancestral resource (wheat flour), and not from novel resources such as finger millet, sorghum, and corn. Notably, the microbiome is not essential for beetle survival and development under any of the tested conditions. Thus, the red flour beetle is a tractable model system to understand the ecology, evolution and mechanisms of host-microbiome interactions, while closely mimicking the host species' natural niche.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Bacillus thuringiensis / pathogenicity
  • Cannibalism
  • Female
  • Fertility
  • Flour / microbiology
  • Flour / parasitology
  • Genetic Fitness
  • Host Microbial Interactions*
  • Longevity
  • Male
  • Microbiota / drug effects
  • Microbiota / genetics
  • Microbiota / radiation effects
  • Models, Biological*
  • Tribolium / growth & development
  • Tribolium / microbiology*
  • Tribolium / physiology
  • Ultraviolet Rays

Substances

  • Anti-Bacterial Agents

Grants and funding

The study was funded by the DBT/Wellcome Trust India Alliance (https://www.indiaalliance.org/) via grant number IA/I/17/1/503091 to DA, and core funding from the National Centre for Biological Sciences to DA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.