Investigation of novel polar lipid signals in planktonic interactions

• Applicant: Dr. Wiebke Grebner
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems ; Oceanography
• Term: from 2015 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 273590342

Phytoplankton contributes to about half of the global primary production and their predator - prey interactions with zooplankton underpin the entire pelagic food web. Yet, the chemical signals that mediate these interactions are largely unknown. Recently, the group of Erik Selander identified copepodamides as the first known group of chemical signals in the interaction of copepods as marine zooplankton predators and phytoplankton species like the harmful algal bloom forming genus Alexandrium. However, the entire function of these compounds as well as the sensing of copepodamides by phytoplankton is still unknown. The proposed research project will focus on two main objectives. The first objective will be the identification of additional novel copepodamide signalling compounds and their copepod species-specific patterns. For this purpose a broad set of chemical separation and detection techniques will be used. The host institute has a unique combination of equipment, facilities, and the know how to support the project, including training in chemical ecology and NMR techniques. The second objective is the identification of copepodamide receptor proteins in the phytoplankton species Alexandrium tamarense and Skeletonema marinoi. The receptor identification will be achieved by different approaches. In cooperation with the group of Julia Kubanek (Georgia Tech, Atlanta, USA), a combination of cell-based assays and electrophysiology will be used. To learn the required methods, a visit at the group of Julia Kubanek is planned. Further, phage display and protein affinity chromatography will be applied to identify the receptor proteins involved in copepodamide perception and their genomic sequence.The predator prey interaction between zooplankton and phytoplankton is crucial for the ecological balance of the pelagic ecosystem and these interactions are mainly regulated by chemical signalling. The identification of these signals and their receptor proteins will lead to a deeper understanding of planktonic interactions. Furthermore, the proposed research project has the potential to act as a Rosetta stone for the deciphering of the influential, but yet unknown chemical language of the open oceans.

• DFG Programme: Research Fellowships
• International Connection: Sweden
• Host: Dr. Erik Selander