Background:
One of the critical challenges of this century – as the planet’s climate shifts at an unprecedented rate – is to gain knowledge about polar phytoplankton, its structure, its diversity, dynamics and resilience, and at the same time prospect ways to monitor and protect it. Among green microalgae, Micromonas (Mamiellophyceae) are main players in Arctic waters, where it dominates the pico-sized phytoplankton populations during the Arctic Spring bloom. Previously thought to be endemic from the Arctic Ocean, Micromonas polaris has been recently reported in Antarctic waters. Our group recently isolated five Micromonas strains from the Antarctic.To the best of our knowledge, these are the first ones on record. The sequencing of gene markers to evaluate the bipolar distribution of M. polaris points to the direction of interconnected populations. Still, it leaves open the question of how recent or frequent the interaction between South and North pole Micromonas populations could be, i.e., if they present or not divergence at the genomic level.
Chlamydomonas, also a green microalgae (Chlorophyceae), is a flagship genus for scientific discovery. It has been extensively studied as a model for photosynthesis, chloroplast biology, cell cycles, and the cell evolution towards multicellularity. Chlamydomonas priscuii (CCMP 1619), was isolated from Lake Bonney, Antarctica. This species has been studied for decades and become a model for the study of cold adaptation. Lake Bonney is a geographically isolated, perennially ice-covered lake located in the Taylor Dry Valleys, South Victoria Land, Antarctica. Our group has recently isolated two (WAP05 and WAP30) new Antarctic Chlamydomonas strains during summer 2019-2020 from the West Antarctic Peninsula (Chile Bay, South Shetland Islands). Molecular identification placed both strains (WAP05 and WAP30) as relatives to C. priscuii UWO241. Besides being geographically distant, the environment from which WAP05/WAP30 were isolated is very different from Lake Bonney. Chile Bay is a marine system with permanent link to open waters, frequent wind-mixing and high-light input when the surface is ice-free during spring-summer.
These groups provide an attractive model for investigating photo-physiological adaptations associated with their ecological successful and niche partition as well as to investigate their resilience to current polar climate stressors (e.g, increase in temperature, decrease in salinity, etc).
What do we want to accomplish?
To increase our understanding of the resilience to climate stressors of polar microalgae this project will center around the following fundamental question:
- Do green microalgae strains (Micromonas and Chlamydomonas) isolated from the Arctic and Antarctic have different responses to environmental stressors?
How do we want to achieve our goal?
To evaluate the impact of different levels of nutrient, salinity, temperature, and light intensity on the growth and survival of green algae isolated from both poles, strains will be submitted to increasing stress conditions using a high-throughput phenotyping unit with 96 wells and an Arduino microcontroller. This device enables the monitoring of cell survival and growth of several strains concomitantly. The level of stress on each treatment will be measured by survival, changes in morphology, and growth rates.
What will you learn during the Master?
- how to grow and cultivate microalgae
- how to evaluate the photo-physiology of microalgae by growth rates and morphology
- how to perform and document your analysis with R language and GitHub
- how to write documents using the LaTeX script language You will have the opportunity to:
- get integrated with PhD-student, postdoc and other Master students participating on distinct projects
- connect with an international network of polar ecologists and algae cultivation platforms
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.
Supervisors:
Assoc Prof Adriana Lopes and co-supervisor: Assoc Prof Catherine Gérikas (Federal University of Parana, Brazil) & Daniel Vaulot (CNRS, French National Centre for Scientific Research)