Influence des facteurs alimentaires et du microbiote intestinal sur la tolérance au stress chez Drosophila melanogaster

Abstract : A large number of environmental parameters constrain insect species, and identifying the elements involved in the adaptation to stressful conditions is crucial. Nutrition is a key factor of this adaptation: it largely controls health of organisms and therefore their stress tolerance. In addition, it is now established that microbiota (i.e. the whole microbial community associated with a host) is much involved in physiological processes of organisms. In particular, gut microbiota is able to modulate host’s nutritional phenotype, resulting in complex dietary-dependent effects. Whether or not gut microbiota can act on stress tolerance is not clear. Thus, using experimental manipulation of microbiota and nutrition, we investigated the outcome of the microbiota-nutrition relationship on Drosophila melanogaster, with a special focus on stress tolerance. We showed a clear dependency of flies on yeasts availability to maintain a normal development, metabolism, and size. Conversely, impaired development resulting from artificial poor diets or from larval crowding was often beneficial for stress tolerance. We demonstrated that microbiota could partially compensate for the absence of yeast resource, but no effects were found in rich food contexts. We observed variable importance of microbiota on thermal tolerance, and attributed this variation to the presence or absence of yeasts. Environmental microorganisms communities were modified by diet composition but gut microbiota was surprisingly stable. Together, these findings highlight the importance of nutritional factors and microbiota in developmental and phenotypical plasticity of fruit flies.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-02067672
Contributor : Abes Star <>
Submitted on : Thursday, March 14, 2019 - 12:11:07 PM
Last modification on : Monday, April 29, 2019 - 2:30:49 PM

File

HENRY_Youn.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-02067672, version 1

Citation

Youn Henry. Influence des facteurs alimentaires et du microbiote intestinal sur la tolérance au stress chez Drosophila melanogaster. Biologie animale. Université Rennes 1, 2018. Français. ⟨NNT : 2018REN1B043⟩. ⟨tel-02067672⟩

Share

Metrics

Record views

75

Files downloads

68