Dokument: cROSstalk - Examination of adaptations and signaling interactions between Hydra and its main bacterial colonizer Curvibacter
| Titel: | cROSstalk - Examination of adaptations and signaling interactions between Hydra and its main bacterial colonizer Curvibacter | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=71505 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20251201-091459-6 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Minten, Timo [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Fraune, Sebastian [Gutachter] Prof. Dr. Beye, Martin [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 570 Biowissenschaften; Biologie | |||||||
| Beschreibung: | Every multicellular organism coexists with a complex microbial community. Together they form the holobiont, a unified biological system essential for host physiology, immunity, and development. The holobiont concept has redefined animal development as a product of dynamic interactions between a host and its associated microbiota, rather than only an autonomous process of the host. The symbiosis between the freshwater polyp Hydra vulgaris and its dominant bacterial colonizer Curvibacter lately has emerged as a powerful model to study inter-kingdom interactions. In this thesis I investigate evolutionary and functional dynamics of this symbiotic relationship and establish a new method to quantify in vivo fluorescence signals in Hydra polyps. Phylogenetic analysis using 16S rRNA and GyrB gene sequencing revealed a strong congruence between the phylogenetic trees of Curvibacter strains isolated from various Hydra species and their corresponding Hydra hosts. Taken together with results from prior studies, this suggests a pattern of co-speciation and phylosymbiosis between Hydra and
Curvibacter. Additionally, I used metatranscriptomic profiling to identify Curvibacter genes involved in host colonization. Most of the top upregulated genes during symbiosis are involved in scavenging of reactive oxygen species (ROS), including the ohrR/ohrA operon. Examination on the presence of ROS in the Hydra holobiont, using a newly established method for high-throughput in vivo imaging of Hydra polyps, revealed that germ-free polyps exhibit elevated ROS levels. Wild type Curvibacter on its own was able to significantly reduce these elevated ROS levels, while a newly created ΔohrR/ohrA mutant failed to do so. These initial findings reveal an important role of Curvibacter in regulating ROS homeostasis in the Hydra holobiont and indicate a possible ROS-mediated effect of this regulation on Hydra developmental pathways. Together, these findings demonstrate that host-microbe interactions are shaped by evolutionary history and fine-scale molecular dialogues, reinforcing Hydra and Curvibacter as a model for unraveling basal principles of holobiont biology. | |||||||
| Lizenz: |  Dieses Werk ist lizenziert unter einer Creative Commons Namensnennung 4.0 International Lizenz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Biologie | |||||||
| Dokument erstellt am: | 01.12.2025 | |||||||
| Dateien geändert am: | 01.12.2025 | |||||||
| Promotionsantrag am: | 11.06.2025 | |||||||
| Datum der Promotion: | 04.11.2025 |
