Labyrinthulomycetes is a group of ubiquitous protists present in marine and estuarine environments with cosmopolitan distribution, from tropics to polar regions. Some species are known for their saprotrophic lifestyle (feeding on dead and decaying organic matter) while others have been described as opportunistic parasites of clams, juvenile abalone, corals, seagrasses and diatoms.
They are characterized by the formation of a network of fine, often branching cytoplasmic threads, extending from cells bodies into the environment. These threads provide adhesion to the substrate and participate in the acquisition of nutrients. It has been also proposed that they adhered to living diatom cells via the tip of these characteristic ectoplasmic net system to extract nutrients.
In contrast with their fungi counterparts (e.g., chytrids), the underpinning ecology and the biology of Labyrinthulomycetes interaction with members of the phytoplankton community (e.g. diatoms) remain little studied. Labyrinthulomycetes and diatoms interactions are generally considered to be detrimental to host populations but it has been also suggested that by selective preying on ”unhealthy” diatom cells, Labyrinthulomycetes improve the overall health of the diatom population.
What do we want to accomplish?
To increase our understanding of the role interactions between phytoplankton (e.g. diatoms) and saprophytic protists (e.g. Labyrinthulomycetes) play in structuring plankton communities, this project will center around the following fundamental questions:
- To which degree, the co-occurrences of Labyrinthulomycetes - diatoms species deviate from random assembly in natural plankton communities?
To investigate patterns of co-occurrence of Labyrinthulomycetes-diatoms species in tropical and temperate coastal waters, we will analyze the metabarcoding sequencing data of protist communities generated from samples acquired monthly/bi-monthly from both temperate (France - SOMLIT-Astan & Norway - Oslofjorden time series) and equatorial (Singapore Times Series) tidally mixed coastal time series over a period of 3 to 5 years.
- What is the nature of Labyrinthulomycetes-diatoms interaction with diatoms (friend or foe?)
In order to characterize the morphological features and changes of both Labyrinthula - diatoms species during the course of this interaction, epifluorescence microscopy observations and scanning electron microscopy images will be obtained from our co-culture SMS89 during its distinct growth phases. SMS89 is a co-culture system between the diatom Triceratium sp. and Labyrinthula sp. obtained from tropical coastal waters.
What will you learn during the Master?
You will learn how to combine laboratory and data analysis tools to investigate interactions among planktonic protists.
You will have the opportunity to:
- join the monthly sampling cruises conducted at the Oslofjorden
- get integrated with PhD-student, postdoc and other Master students participating on the Oslofjorden time series
You will learn:
- how to manipulate and work with large metabarcoding datasets using R
- how to document your analysis workflows with GitHub and RMarkdown
- how to isolate and cultivate phytoplankton cells
- how to write documents using the LaTeX script language
- how to investigate ultra-structure cellular changes using Electron microcopy 1
What can we offer?
We offer a safe space for learning through achievements and failures, alone and in partnership with others. We welcome individuals of all ages, backgrounds, beliefs, ethnicities, genders, gender identities, gender expressions, national origins, religious affiliations, sexual orientations, and any other visible and non-visible differences. All members of our research groups are expected to contribute to a respectful, welcoming and inclusive environment for every other member.
supervisor: Assoc Prof Adriana Lopes (GEEK Laboratory) and co-supervisors: Assoc Prof Wenche Eikrem & Assoc Prof Micah Dunthorn (Natural History Museum)