biostudies-literatureEzzedine JAHuman Frontier Science ProgramAgence Nationale de la RechercheHuman Frontier Science Program (HFSP)Agence Nationale de la Recherche (French National Research Agency)7500https://www.ebi.ac.uk/biostudies/studies/S-EPMC10657455biostudies-literatureUnknown14(1)Sanguina nivaloides is the main alga forming red snowfields in high mountains and Polar Regions. It is non-cultivable. Analysis of environmental samples by X-ray tomography, focused-ion-beam scanning-electron-microscopy, physicochemical and physiological characterization reveal adaptive traits accounting for algal capacity to reside in snow. Cysts populate liquid water at the periphery of ice, are photosynthetically active, can survive for months, and are sensitive to freezing. They harbor a wrinkled plasma membrane expanding the interface with environment. Ionomic analysis supports a cell efflux of K+, and assimilation of phosphorus. Glycerolipidomic analysis confirms a phosphate limitation. The chloroplast contains thylakoids oriented in all directions, fixes carbon in a central pyrenoidNature communicationsAdaptive traits of cysts of the snow alga Sanguina nivaloides unveiled by 3D subcellular imaging.PMC10657455ANR-20-CE02-0020RGP0046/2018Schilling MLiger LHagenmuller PDevime FEzzedine JAUwizeye CJouhet JMarechal ERavanel SSalze PAmato APetroutsos DFalconet DVillain GGallet BSi Larbi GStewart AJouneau PHLouwagie MDumont MValay JGfalseAdaptive traits of cysts of the snow alga Sanguina nivaloides unveiled by 3D subcellular imaging.Sanguina nivaloides is the main alga forming red snowfields in high mountains and Polar Regions. It is non-cultivable. Analysis of environmental samples by X-ray tomography, focused-ion-beam scanning-electron-microscopy, physicochemical and physiological characterization reveal adaptive traits accounting for algal capacity to reside in snow. Cysts populate liquid water at the periphery of ice, are photosynthetically active, can survive for months, and are sensitive to freezing. They harbor a wrinkled plasma membrane expanding the interface with environment. Ionomic analysis supports a cell efflux of K+, and assimilation of phosphorus. Glycerolipidomic analysis confirms a phosphate limitation. The chloroplast contains thylakoids oriented in all directions, fixes carbon in a central pyrenoid2023-01-01T00:00:00Z2023 Nov2025-04-25T20:05:26.943Z2025-04-06T08:12:37.807ZS-EPMC106574553798036010.1038/s41467-023-43030-7