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.
Bacteria, oxidative environment, symbiotic associations, squid, insects