Description du projet
Une recherche étudie la relation entre les coléoptères carabidés et les bactéries symbiotiques
L’élucidation des principales adaptations qui sous‑tendent le succès de l’évolution reste un défi central pour l’évolution et l’écologie. Le projet SYMBeetle, financé par l’UE, étudiera l’évolution d’un processus d’adaptation clé assisté par des symbiotes qui protège les coléoptères carabidés de la déshydratation et des prédateurs. De nouvelles preuves ont montré que des coléoptères carabidés issus d’au moins sept familles différentes sont devenus dépendants de la symbiose pour l’approvisionnement d’une substance importante — la tyrosine. Cet acide aminé aromatique est nécessaire à la biosynthèse des cuticules, au durcissement et au tannage. Les symbioses de ce type ont évolué de manière indépendante à de nombreuses reprises et ont probablement constitué un facteur clé permettant aux coléoptères carabidés de se propager dans de nouvelles niches écologiques.
Objectif
To elucidate the key adaptations underlying evolutionary success remains one of the central challenges in evolution and ecology. However, rigorous experimental tests are usually hampered by the lack of replicate evolutionary events or the inability to manipulate a candidate trait of importance. SYMBeetle exploits the naturally replicated evolution of an experimentally tractable, symbiont-assisted key adaptation in beetles to understand its impact on niche expansion and diversification. Recent evidence indicates that beetles across at least seven different families associate with microbial symbionts that provision their host with tyrosine, an aromatic amino acid necessary for cuticle biosynthesis, hardening, and tanning. SYMBeetle addresses the hypothesis that the acquisition of tyrosine-supplementing microbes constituted a key innovation across phylogenetically distinct beetles that allowed them to expand into novel ecological niches, by relaxing the dependence on nitrogen-rich diets for successful formation of the rigid exoskeleton and protective front wings. Specifically, tyrosine supplementation may facilitate the transition to herbivory and allow for subsisting at very low ambient humidity, by facilitating the production of a thick cuticular barrier to desiccation. To test this, SYMBeetle will uniquely combine experimental manipulation of symbiotic associations to assess the symbionts’ contribution to cuticle biosynthesis and its fitness consequences (desiccation resistance and defense) with large-scale comparative approaches aimed at elucidating the taxonomic distribution, ecological contexts, and evolutionary origins of cuticle-supplementing symbioses. The results are expected to transform our understanding of microbes as important facilitators for the evolution of herbivory and the colonization of dry habitats in beetles, two factors of major relevance for the emergence of economically relevant insect pests of agricultural crops and stored products.
Champ scientifique
- natural sciencesbiological sciencesecology
- natural sciencesbiological sciencesevolutionary biology
- medical and health scienceshealth sciencesnutrition
- natural sciencesbiological sciencesbiological behavioural sciencesethologybiological interactions
- natural scienceschemical sciencesorganic chemistryamines
Programme(s)
Régime de financement
ERC-COG - Consolidator GrantInstitution d’accueil
80539 Munchen
Allemagne