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Title: Effect of gut microbiota on α‐amanitin tolerance in Drosophila tripunctata
Abstract

The bacterial gut microbiota of many animals is known to be important for many physiological functions including detoxification. The selective pressures imposed on insects by exposure to toxins may also be selective pressures on their symbiotic bacteria, who thus may contribute to the mechanism of toxin tolerance for the insect. Amatoxins are a class of cyclopeptide mushroom toxins that primarily act by binding to RNA polymerase II and inhibiting transcription. Several species of mycophagousDrosophilaare tolerant to amatoxins found in mushrooms of the genusAmanita, despite these toxins being lethal to most other known eukaryotes. These species can tolerate amatoxins in natural concentrations to utilize toxic mushrooms as larval hosts, but the mechanism by which these species are tolerant remains unknown. Previous data have shown that a local population ofD. tripunctataexhibits significant genetic variation in toxin tolerance. This study assesses the potential role of the microbiome in α‐amanitin tolerance in six wild‐derived strains ofDrosophila tripunctata. Normal and antibiotic‐treated samples of six strains were reared on diets with and without α‐amanitin, and then scored for survival from the larval stage to adulthood and for development time to pupation. Our results show that a substantial reduction in bacterial load does not influence toxin tolerance in this system, while confirming genotype and toxin‐specific effects on survival are independent of the microbiome composition. Thus, we conclude that this adaptation to exploit toxic mushrooms as a host is likely intrinsic to the fly's genome and not a property of their microbiome.

 
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Award ID(s):
1737869
NSF-PAR ID:
10442883
Author(s) / Creator(s):
 ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Ecology and Evolution
Volume:
10
Issue:
17
ISSN:
2045-7758
Page Range / eLocation ID:
p. 9419-9427
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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