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Research Project: Identification of the Ecological Niches and Development of Intervention Strategies to Reduce Pathogenic Foodborne Pathogens in Poultry

Location: Food and Feed Safety Research

Title: Indole: An evolutionarily conserved influencer of behavior across kingdoms

item TOMBERLIN, JEFFERY - Texas A&M University
item Crippen, Tawni - Tc
item WU, GUOYAO - Texas A&M University
item GRIFFIN, ASHLEIGH - University Of Oxford
item WOOD, THOMAS - Pennsylvania State University
item KILNER, REBECCA - Cambridge University

Submitted to: Bioessays
Publication Type: Review Article
Publication Acceptance Date: 12/23/2016
Publication Date: 2/17/2017
Citation: Tomberlin, J.K., Crippen, T.L., Wu, G., Griffin, A.S., Wood, T.K., Kilner, R.M. 2017. Indole: An evolutionarily conserved influencer of behavior across kingdoms. Bioessays. 39(2):1600203.

Interpretive Summary: In this review, we have attempted to explain why indole is so universally found and used in nature, and how it affects diverse organisms. The initial portion covers the biochemistry of indole to identify special properties that might explain its interactions among organisms. It includes a brief primer in the terminology and concepts from evolutionary communication theory. We review the types of interactions within and among animal kingdoms and attempt to classify those using existing concepts from the theory of animal communication. We suggest that indole is used so universally because it derives from tryptophan, an essential resource for many species, yet rare in nature. Indole is used to coordinate actions within organisms and influence the behavior of species that belong to other kingdoms. We suggest that future work could use indole to manage crop pests, promote pollination, and control insect vectors of pathogens.

Technical Abstract: Indole, which is produced from the breakdown of the essential amino acid tryptophan, is a key environmental cue that is used by many organisms. But why is its use so ubiquitous, and how does it function to modulate interactions among such diverse organisms? Here, we review the literature to address these questions. Based on its biochemistry, we suggest that indole is used so universally, and by such different organisms, because it derives from the metabolism of tryptophan, a resource that is essential for many species yet rare in nature. These properties make it a valuable environmental cue for resources that are almost universally important for promoting fitness. We then describe how indole is used to coordinate actions within organisms, to influence the behavior of conspecifics, and can even be used to change the behavior of species that belong to other kingdoms. Drawing on the evolutionary framework that has been developed for understanding animal communication, we show how this is diversely achieved by indole acting as a cue, a manipulative signal, and an honest signal, as well as how indole can be used synergistically to amplify information conveyed by other molecules. Clarifying these distinct functions of indole identifies patterns that transcend different kingdoms of organisms and is important for understanding how indole might be used in the future to manage pests, regulate pollination, and control vectors of pathogens.