Biovitenskap (master)

The microscopic anatomy and cell biology of the unique alga: Hydrurus foetidus

Names of the supervisors: Xian Hu, Jens ?dne Rekkedal Haga, Oddmund Bakke
Collaborators: as defined by the project
Preferred project period: September 2025 – June 2027

Abstract

Hydrurus foetidus (Villars) Trevisan is a benthic freshwater alga belonging to the class Chrysophyceae. Under seasonal climatic conditions, this alga is predominantly found in rivers during colder months. It exhibits a broad distribution across cold-temperate, polar, and periglacial regions, with notable populations in the vicinity of Finse Alpine Research Centre. In these cold stream environments, H. foetidus has evolved multicellularity independent of other lifeforms and thus has unique solutions to tissue formation and controlled cell division. How the cells regulate controlled cell division and tissue formation is unknown.

Introduction

The primary objective of this research is to perform live cell imaging of H. foetidus using state of art optical microscopy techniques. We aim to document the how the cells interact and form different anatomical tissue types and perhaps different organs. We have previously discovered a so far undescribed and unique organ type that might be part of this project.

Objectives

The primary objective of this research is to perform live cell imaging of H. foetidus using state of art optical microscopy techniques including FLIM. We aim to document the life cycle stages of this alga and investigate the formation and significance of the aggregates observed in nature. By examining the environmental factors and biological processes influencing aggregation, we hope to gain insights into the ecology of this unique organism.

Methodology

Sampling and fieldwork will be done at the Finse Alpine Research Centre while advanced microscopy techniques will be carried out at the NorMIC Imaging Platform in Oslo, especially the newest STED FLIM microscope (https://www.mn.uio.no/ibv/english/research/infrastructure/facilities/life-science/imaging/normic/instruments/sted.html).

By employing both bright field and fluorescence microscopy, we will be able to capture dynamic processes of the cell population and assess their functionality during different life cycle stages. The observational data will be compiled to generate a detailed description of the Norwegian population of H. foetidus and its life cycle. Hydrurus foetidus has been fully sequenced, and a follow-up would be to use this information for genetic analysis combined with imaging that might lead mechanisms and molecules that are involved in.

Preliminary Data

^{Fluorescence lifetime image of autofluorescence from H. foetidus.}
^{Sample: Jens ?dne Rekkedal Haga, Julien Resseguier, Imaging: Xian Hu}

Expected Outcomes

The student will learn both how to do fieldwork and sampling in alpine environments and state of the art microscopy techniques, including tissue preparation, fixation, sectioning etc. We anticipate that the findings from this study will contribute significantly to our understanding of H. foetidus and it has evolved multicellularity. The results will culminate in a descriptive publication of the microscopic anatomy of H. foetidus.

Location

The student will spend approximately half of the study time in Finse Biostation and the other half at NorMIC Imaging Platform. The actual percentage might vary as defined by the project.