Water mass specific genes dominate the Southern Ocean microbiome
The Southern Ocean (SO) plays a key role in regulating global biogeochemical cycles and climate, yet microbial genes sustaining its biological activity remain poorly characterized. We introduce a microbial genes collection from 218 metagenomes sampled during the Antarctic Circumnavigation Expedition, the majority of which are missing from functional databases. 38% even lack homologs in current reference marine gene catalogs, defining a singular genetic seascape. We show that SO gene assemblages exhibit a common polar signature with the Arctic Ocean while being structured by water masses at the SO-scale. We analyze genomic markers of diverse SO biomes, focusing on dimethylsulphoniopropionate (DMSP) cleavage by polar-adapted bacteria, organic matter consumption in the blooming Mertz polynya and adaptation to polar conditions in the ubiquitous bacteria Pelagibacter. Our work takes a step towards a comprehensive understanding of SO's plankton ecology and evolution, capturing the current state of the unique microbial diversity in this rapidly changing Ocean.
Authors
- Jolann Pommellec
- Corinne Da Silva (ORCID: https://orcid.org/0000-0002-7618-7831)
- Julie Poulain (ORCID: https://orcid.org/0000-0002-8744-3116)
- Frédérick Gavory (ORCID: https://orcid.org/0000-0003-1534-5725)
- Cyril Noël (ORCID: https://orcid.org/0000-0002-7139-4073)
- Antonio Fernàndez-Guerra (ORCID: https://orcid.org/0000-0002-8679-490X)
- P. Wincker
- Aude Perdereau (ORCID: https://orcid.org/0000-0001-7125-5308)
- Marion Fourquez (ORCID: https://orcid.org/0000-0001-5395-4877)
- Lisa-Marie Delpech (ORCID: https://orcid.org/0009-0006-0154-0211)
- Ulysse Guyet (ORCID: https://orcid.org/0000-0002-3603-5382)
- Nicolas Cassar (ORCID: https://orcid.org/0000-0003-0100-3783)
- Chiara Vanni (ORCID: https://orcid.org/0000-0002-1124-1147)
- Emile Faure (ORCID: https://orcid.org/0000-0002-9049-2269)
- Alexandre Cormier (ORCID: https://orcid.org/0000-0002-7775-8413)
- Marie-Noëlle Houssais
- Yajuan Lin
- Lois Maignien
- Christel Hassler
- Karine Labadie
- A. Murat Eren
Institutions
- École Normale Supérieure de Lyon (FR)
- University of Copenhagen (DK)
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (DE)
- Centre National de la Recherche Scientifique (FR)
- University of Tasmania (AU)
- Carl von Ossietzky Universität Oldenburg (DE)
- Australian Antarctic Division (AU)
- Marine Biological Laboratory (US)
- Ifremer (FR)
- Université de Bretagne Occidentale (FR)
- Duke University (US)
- University of Bremen (DE)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- Station Biologique de Roscoff (FR)
- Sorbonne Université (FR)
- Helmholtz Institute for Functional Marine Biodiversity (DE)
- LIttoral ENvironnement et Sociétés (FR)
- Max Planck Institute for Marine Microbiology (DE)
- Genoscope (FR)
- Adaptation et Diversité en Milieu Marin (FR)
- Lundbeck Foundation (DK)
- CEA Paris-Saclay (FR)
- Swiss Polar Institute (CH)
- Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (FR)
- Laboratoire des Sciences de l'Environnement Marin (FR)
- Institut de Recherche pour le Développement (FR)
- École Polytechnique Fédérale de Lausanne (CH)
- Texas A&M University – Corpus Christi (US)
- University of Lausanne (CH)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-03-09
- DOI
- https://doi.org/10.1038/s41467-026-69584-w
- Primary Topic
- Microbial Community Ecology and Physiology
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- European Molecular Biology Laboratory
- Agence Nationale de la Recherche
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Consiglio Nazionale delle Ricerche
- Swiss Polar Institute