PIF2024 - MECANISMOS DE COORDINACION ENTRE LA CIANOBACTERIA UNICELULAR MARINA FIJADORA DE NITROGENO UCYN-A Y SU ALGA HOSPEDADORA (PID2023-152110NA-I00)

Symbiotic interactions have been key to evolution on Earth. The success of eukaryotes was possible due to the establishment of endosymbiotic relationships between unicellular microorganisms that gave rise to specialized organelles (chloroplasts and mitochondria), yet the early steps underpinning such biological innovations are still unresolved. Recently, it was found that a widely distributed marine nitrogen-fixing cyanobacterium (UCYN-A), which is in obligate symbiosis with a single-celled planktonic alga (Braarudosphaera bigelowii), has undergone genome rearrangements analogous to those happening during organelle evolution. However, very little is known about the chemical communication between UCYN-A and B. bigelowii. Besides, UCYN-A and B. bigelowii have a synchronized cell division, yet the mechanisms behind such a fine regulation are completely unknown. This project is designed to address fundamental questions in the evolution of the B. bigelowii/UCYN-A symbiosis by the combination of novel genomic approaches, and also will bring the sub-cellular localization of key metabolic processes a step forward through the application of the immunolabeling approach together with epifluorescence microscopy. The COMMUNAS project will address issues currently identified as of high importance by leading experts in the field, including the study of complex cell-to-cell interactions and the effect that biotic interactions have on shaping biogeochemical cycles in natural ecosystems.