Research
How do cellular and molecular determinants evolve in order to enable organisms to sense and adapt to their specific niche in the environment? Understanding how information is encoded in a meaningful way is a fundamental problem of all living organisms and the analysis of sensory systems provides insight into the basic principles by which cells detect and integrate diverse signals.
In the lab we are interested in cellular physiology. We use different techniques ranging from behavior, anatomy and molecular biology to electrophysiology, to understand how cellular and molecular determinants evolved in order to enable organisms to sense and adapt to their specific niche in the environment. We investigate these questions in the context of ecologically relevant behaviors, such as habitat choice and hunting using marine invertebrates (Octopus and Corals).
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​How do marine animals detect chemical signals in the vastness of the ocean?
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Sensory specialists such as the Octopus, are good models to study specialized sensory modalities like for example chemo-tactile sensation. Investigation into this virtually unexplored ‘touch-taste’ sense led to the description of a novel family of chemotactile receptors (CRs) that mediate the octopus’ contact-dependent, aquatic chemosensation. CRs are found specifically in cephalopods, expressed in suction cups (suckers) along the arms, and mediate the detection of poorly-soluble terpenoid molecules from natural products which act as ‘touch-taste’ stimuli in aquatic environments (van Giesen et al. 2020, Kang et al 2023).
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Animals rely on their sensory systems to detect and filter signals from a noisy environment. However, recent anthropogenic influence has changed many ecosystems, including the ocean in a quite extreme way, and is threatening the very existence of many species. Understanding which cellular and molecular mechanisms are employed to filter sensory signals important for survival will help us to understand how animals cope with rapid changes in their sensory Umwelt.
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ERC Project: "EnvIronchannel"
Corals form the basis for some of the most diverse marine ecosystems on the planet- ecosystems, which have suffered tremendous harm due to anthropogenic influences and are predicted to be among the most adversely affected habitats under the foreseen changes in climate. Yet very little is known about how many coral species sense and interact with their environment.
Among these changing conditions are the occurrence and composition of microorganisms in the coral’s habitat, which are affected by changes in temperature and pH. Corals associate with several specific microorganisms, that govern central aspects of their complex lifecycle, such as the recruitment of larvae, a process that ensures health and resilience of coral reefs.
While the central role of biofilms is established in tropical coral species, the vast deep-sea cold-water coral species are less well studied. Lophelia Pertusa is a framework-forming cold-water coral with a global distribution and important ecosystem function – and lucky for us accessible here in Trondheim. We will study whether larval recruitment depends on biofilm abundance and composition and how the animals are capable of finding and recognizing the right place to settle.
Methods and Facilities
Cold water coral lab
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At TBS (Trondhjem biologiske stasjon), we have our cold water coral lab housing mostly Lophelia pertusa (Desmophylum pertusum). This beautiful cold water coral is endemic to the fjord and we sample the animals with the Gunnerus and the ROV from around 200 meters in collaboration with AURLabs.
Lophelia polyps can be housed in the tanks where they get water supplied from 100 meters deep in the fjord. The animals spawn in the lab (sometimes) during their annual spawning event in February. We study the biology of how their larvae decide where and how to settle, generously supported by an ERC grant.
Eledone cirrhosa
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Understanding how animals adapt to their specific environmental niche is one of our big passions. Cephalopods are sensory specialists and E. cirrhosa is a local octopus species that lives in the dark norwegian sea. How do these animals sense their environment? Ocotpus possess hundreds of sucker cups with thousands of sensory cells, but many mysteries about their sensory abilities are only just being discovered. We are trying to understand some of the fundamental questions of their sensory biology using behaviour, transcriptomics and electrophysiology. Our animals are housed at NTNU Sealabs where they get salmon quality water (in other words the very best). This work is generously founded by the norwegian research council.
Cellular physiology
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In the lab we have two patch clamp electrophysiology set ups that we use to study various aspects of the physiology of strange animals and the ion channels that mediate sensory perception and cellular information coding in these critters. One of the setups is equiped with a camera to so we can study other aspects as for example movement of coral larvae. We also have a TVEC set up which we use to study ion channel biophysics in more detail using heterologous expression in Xenopus oocytes.
To achieve these goals, we use transcriptomic analysis to identify channels and receptors that are relevant to behavior. We combine genomics, functional studies, molecular biology and behavior to understand how animals adapt to an ever changing environment.
If you are interessted in collaboration or want more details about these projects just write an email.
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lena.van.giesen@ntnu.no​​
