Third Party funded projects
2023 - 2026 Heisenberg grant DFG
Function and evolution of intracellular symbioses in marine invertebrates
Nutritional mutualism is ubiquitous in nature and strongly impacts host biology. Even though all early branching animals are marine, much of the biology of these enigmatic animals is unexplored, especially their associations with intracellular and beneficial microbes for nutritional mutualism. Among bacteria, Alphaproteobacteria are masters of nutritional mutualism and intracellular life. Their intracellular interactions have massively participated in the evolution of life on earth, from forging the eukaryote cell to providing essential nutrients such as nitrogen in land plants. I will study how marine and early branching animal hosts interact with their beneficial alphaproteobacterial symbionts at the cellular and molecular level and how these interactions have evolved and continue to shape the ecology of their hosts. The proposed research will generate fundamental insights into the function and the evolution of intracellular and nutritional symbioses that alter physiology, ecology, and gene flow from within host cells.
2023 - 2026 Paracatenula project DFG
Evolution and intracellular cooperation in an ancient nutritional symbiosis
Intracellular symbiosis is a key source for evolutionary innovation and, e.g., allows animal hosts to directly rely on chemosynthesis for nutrition. This project focuses on the evolution and function of one of the most deeply integrated animal-bacterial intracellular symbioses in metazoans - mouthless Paracatenula flatworms and their chemosynthetic Riegeria symbionts. Compared to the highly reduced nutritional symbionts in insects, Riegeria encodes a much more versatile metabolism that can generate all building blocks of life. In the first part of this project, we will test how the evolutionary dynamics are affected by this large and essential core genome by comparatively analyzing metagenomic datasets of 38 globally sampled host species. The second part of the project will unravel the mechanisms of cellular metabolic integration. The Riegeria symbionts produce PHA bioplastics for storage that animals cannot use. Surprisingly, the symbionts possess no PHA depolymerase, but instead, the hosts express several variants of this essential enzyme for PHA use. We will analyze the function and the expression patterns in the host and will explore a possible transfer of such enzymes to the symbiont, testing for organelle-level intracellular integration.
2024 - 2027 C1 project in the CRC 1182
Impact of symbiosis on life history decisions at the base of the metazoan evolution: lessons from placozoans and Hydra
The tandem PI project C1 (PIs Bosch, Gruber-Vodicka) aims to explore the impact of microbes on senescence and life history switches in very early branching metazoans Hydra and placozoans, using a comparative approach. This includes a focus on the role of the microbiome in the maintenance of non-senescence in H. oligactis polyps during a switch from asexual to sexual reproduction and the role of intracellular Midichloriaceae (Alphaproteobacteria) in life history switches in placozoans and Hydra.
2023 - 2026 Heisenberg grant DFG
Function and evolution of intracellular symbioses in marine invertebrates
Nutritional mutualism is ubiquitous in nature and strongly impacts host biology. Even though all early branching animals are marine, much of the biology of these enigmatic animals is unexplored, especially their associations with intracellular and beneficial microbes for nutritional mutualism. Among bacteria, Alphaproteobacteria are masters of nutritional mutualism and intracellular life. Their intracellular interactions have massively participated in the evolution of life on earth, from forging the eukaryote cell to providing essential nutrients such as nitrogen in land plants. I will study how marine and early branching animal hosts interact with their beneficial alphaproteobacterial symbionts at the cellular and molecular level and how these interactions have evolved and continue to shape the ecology of their hosts. The proposed research will generate fundamental insights into the function and the evolution of intracellular and nutritional symbioses that alter physiology, ecology, and gene flow from within host cells.
2023 - 2026 Paracatenula project DFG
Evolution and intracellular cooperation in an ancient nutritional symbiosis
Intracellular symbiosis is a key source for evolutionary innovation and, e.g., allows animal hosts to directly rely on chemosynthesis for nutrition. This project focuses on the evolution and function of one of the most deeply integrated animal-bacterial intracellular symbioses in metazoans - mouthless Paracatenula flatworms and their chemosynthetic Riegeria symbionts. Compared to the highly reduced nutritional symbionts in insects, Riegeria encodes a much more versatile metabolism that can generate all building blocks of life. In the first part of this project, we will test how the evolutionary dynamics are affected by this large and essential core genome by comparatively analyzing metagenomic datasets of 38 globally sampled host species. The second part of the project will unravel the mechanisms of cellular metabolic integration. The Riegeria symbionts produce PHA bioplastics for storage that animals cannot use. Surprisingly, the symbionts possess no PHA depolymerase, but instead, the hosts express several variants of this essential enzyme for PHA use. We will analyze the function and the expression patterns in the host and will explore a possible transfer of such enzymes to the symbiont, testing for organelle-level intracellular integration.
2024 - 2027 C1 project in the CRC 1182
Impact of symbiosis on life history decisions at the base of the metazoan evolution: lessons from placozoans and Hydra
The tandem PI project C1 (PIs Bosch, Gruber-Vodicka) aims to explore the impact of microbes on senescence and life history switches in very early branching metazoans Hydra and placozoans, using a comparative approach. This includes a focus on the role of the microbiome in the maintenance of non-senescence in H. oligactis polyps during a switch from asexual to sexual reproduction and the role of intracellular Midichloriaceae (Alphaproteobacteria) in life history switches in placozoans and Hydra.
Research collaborations
2012 - ongoing Stilbonematinae biodiversity, ecology, and evolution
Together with J.A. Ott and his team at the University of Vienna, we are characterizing the marine Nematode subfamily Stilbonematinae, which lives in conspicuous symbiosis with chemosynthetic gammaproteobacterial ectosymbionts. The symbionts have characteristic and host-genus-specific growth forms, from extremely long filaments to biofilms of coccoid cells or columnar single-layer rods. We are interested in the ecology, evolution, and diversity of this enigmatic group of shiny white marine nematodes that occur around the world and that can dominate meiofaunal communities.
2012 - ongoing Stilbonematinae biodiversity, ecology, and evolution
Together with J.A. Ott and his team at the University of Vienna, we are characterizing the marine Nematode subfamily Stilbonematinae, which lives in conspicuous symbiosis with chemosynthetic gammaproteobacterial ectosymbionts. The symbionts have characteristic and host-genus-specific growth forms, from extremely long filaments to biofilms of coccoid cells or columnar single-layer rods. We are interested in the ecology, evolution, and diversity of this enigmatic group of shiny white marine nematodes that occur around the world and that can dominate meiofaunal communities.