SYMBIOX

Role of the oxidative environment in the stability of symbiotic associations

 Partecipanti

Mappa

 Word cloud

Esplora la "nuvola delle parole (Word Cloud) per avere un'idea di massima del progetto.

 Obiettivo del progetto (Objective)

'Associations between eukaryotes and microorganisms are frequently observed in nature. They are highly diverse and range along a continuum between parasitism and mutualism. Although numerous symbiotic associations have been well described at the phenotypic level, the mechanisms involved in the maintenance of the association and their evolutionary consequences are rarely studied. However, the presence of a permanent resident can have direct consequences on the host developmental program and immune system, and dramatically change the outcome of a secondary infection by a pathogen. As the oxidative environment is known to play pleiotropic roles in development and immunity, I propose to determine to what extent its control plays a role in the stability of symbiotic associations and in the evolution of both partners. To address these issues, I plan to work on various symbiotic associations, differing in the characteristics of the symbiotic relationship. I will focus on two monospecific interactions between invertebrates and bacteria (Squid/Vibrio, Insect/Wolbachia), natural but easily examined systems for defining the biochemical/genetic events that underlie long-term infection by non-pathogenic bacteria. In each model system, I will first characterize the molecular mechanisms involved in the control of the oxidative environment, then determine how the oxidative environment varies in response to symbiosis, and finally assess to what extent its regulation affects the stability of the symbiosis. In particular, I propose to determine if: 1) the symbiont manipulates the host oxidative environment to favour its maintenance, 2) the host evolves to tolerate the presence of the symbiont, and 3) changes of the oxidative environment only constitute a by-product of the symbiotic association. Finally, the comparative analysis will allow me to determine potential shared mechanisms that play a key role in the maintenance of symbiotic associations.'

Introduzione (Teaser)

Scientists have uncovered molecular and biochemical mechanisms behind how animal hosts respond to bacterial signalling to select and keep the bacteria.

Descrizione progetto (Article)

Beneficial symbiotic relationships between organisms and bacteria are now known to play key roles in human processes like immunity and digestion. What is less known, however, is how these associations are established and maintained, and the consequences such interactions have on the evolution of both partners.

The EU-funded 'Role of the oxidative environment in the stability of symbiotic associations' (SYMBIOX) project examined this by comparing bacterial relationships in squid and insects. Specifically, the project investigated how oxygen reactions affect symbiotic associations in relation to immunity, development and metabolism.

Researchers characterized an oxygen-binding protein, the haemocyanin, which plays a role in selecting specific bacteria from plankton to enter the host, and in favouring light production by symbionts. They also deciphered how perturbations of the oxidative environment, induced by bacteria, can affect host physiology and the symbiotic relationship between partners.

Overall, the project found that the oxidative environment is key in the evolution of symbiotic relationships. Scientists found that both the host and the bacteria can affect the oxidative environment, which hence plays a role of mediator of communication between partners. The regulation of the oxidative environment is thus involved during the establishment, the persistence and the break down of symbiotic associations, and influences the evolution and stability of symbiotic associations.

This research could have applications in medicine and agriculture, as it could provide insight into universal mechanisms involved in controlling mutualists and pathogens, and their consequences on human response to infections or pest control strategies.