Metabolic mechanisms for the evolution of stable symbiosis

摘要: Endosymbiosis involves the merger of once independent organisms; this evolutionary transition has defined history eukaryotes and continues to underpin function a wide range ecosystems. Endosymbioses are evolutionarily dynamic because inherent conflict between self-interest partners make breakdown interaction ever-likely is exacerbated by environmental context dependence benefits symbiosis. This necessitates selection for partner switching, which can reshuffle genetic identities symbiotic partnerships so rescue symbioses from cheater-induced extinction enable rapid adaptation change. However, mechanisms partner-specificity, that underlie potential unknown. Here I report metabolic control specificity within tractable microbial photosymbiosis Paramecium bursaria Chlorella . have found function, not identity, enables partner-switching, but variation plays an important role in maintaining phenotype. In addition, observed symbiont stress-responses played specificity, alleviating stress responses may be strategy generalist host genotypes. Furthermore, used experimental evolution show novel, initially non-beneficial association rapidly evolve become beneficial These results demonstrate integration compatibility maladapted host-symbiont pairings overcome their lack co-adaptation through alterations metabolism regulation. Understanding process novel switching crucial if we understand how new originate stabilise. Moreover, mechanistic knowledge required mitigate performing ecosystem functions driven change, such as coral reefs