PT  - JOURNAL ARTICLE
AU  - Nils Rädecker
AU  - Jean-Baptiste Raina
AU  - Mathieu Pernice
AU  - Gabriela Perna
AU  - Paul Guagliardo
AU  - Matt R Kilburn
AU  - Manuel Aranda
AU  - Christian R Voolstra
TI  - Aiptasia as a model to study metabolic diversity and specificity in cnidarian-dinoflagellate symbioses
AID  - 10.1101/223933
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 223933
4099  - http://biorxiv.org/content/early/2017/11/22/223933.short
4100  - http://biorxiv.org/content/early/2017/11/22/223933.full
AB  - The symbiosis between cnidarian hosts and microalgae of the genus Symbiodinium provides the foundation of coral reefs in oligotrophic waters. Understanding the nutrient-exchange between these partners is key to identifying the fundamental mechanisms behind this symbiosis. However, deciphering the individual role of host and algal partners in the uptake and cycling of nutrients has proven difficult, given the endosymbiotic nature of this relationship. In this study, we highlight the advantages of the emerging model system Aiptasia to investigate the metabolic diversity and specificity of cnidarian – dinoflagellate symbiosis. For this, we combined traditional measurements with nano-scale secondary ion mass spectrometry (NanoSIMS) and stable isotope labeling to investigate carbon and nitrogen cycling both at the organismal scale and the cellular scale. Our results suggest that the individual nutrient assimilation by hosts and symbionts depends on the identity of their respective symbiotic partner. Further, δ13C enrichment patterns revealed that alterations in carbon fixation rates only affected carbon assimilation in the cnidarian host but not the algal symbiont, suggesting a ‘selfish’ character of this symbiotic association. Based on our findings, we identify new venues for future research regarding the role and regulation of nutrient exchange in the cnidarian - dinoflagellate symbiosis. In this context, the model system approach outlined in this study constitutes a powerful tool set to address these questions.