Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Host or symbiont? Proteomics gives new insights into reef organisms’ reaction to environment stress

28.02.2018

Similar to corals, foraminifera in tropical reefs bleach as the water temperature rises. In research, these unicellular organisms can help to investigate the effects of climate change on calcifying organisms. Scientists from Bremen and Dortmund have analysed how tropical foraminifera and their symbiotic algae deal with rising sea temperatures on a molecular level. New proteomics methods have now for the first time enabled them to differentiate between host and symbiont reactions to thermal stress. The results of the project, funded by the Leibniz competition, have been published in the journal Scientific Reports.

Researchers from the Leibniz Centre for Marine Tropical Research (ZMT) in Bremen, the Leibniz Institute for Analytical Sciences (ISAS) in Dortmund and the University of Bremen have been involved in this publication.


Foraminifera Amphistegina lessonii: The green-brown colouration in the upper left corner shows the symbionts, which have moved into the outer chamber. The Foraminifera has a diameter of around 1mm.

© Marleen Stuhr, Leibniz Centre for Tropical Marine Research (ZMT)


A partially bleached foraminifera Amphistegina gibbosa under the fluorescence microscope after one month of thermal stress (32°C).

© Erik Freier, Leibniz Institute for Analytical Sciences (ISAS)

Foraminifera are found throughout the ocean – from the intertidal zone to the deepest ocean trenches, from the tropics to the poles. Some species float in the water as plankton, others live on the seabed. Since they form a calcareous casing, these tiny organisms play an important role in reefs in the formation of sediment.

Like tropical corals, some types of foraminifera can only exist in symbiosis with algae. These symbionts live in the cell of their host organisms and supply them with energy. Under changed environmental conditions, such as rising water temperature or light intensity, the protein composition of foraminifera and their symbiotic algae changes. This can damage the community and lead to bleaching, similar to coral bleaching.

A systematic analysis of the proteins, i.e. proteomics, can provide information about the physiological state of the organism. But who is ultimately responsible for the stress response: the foraminifera and thus the host, or the algae, the symbiont?

ZMT scientist Marleen Stuhr investigated this question in her doctoral thesis under the guidance of Professor Hildegard Westphal (Workgroup Geoecology and Carbonate Sedimentology). Over various periods and intervals Stuhr exposed foraminifera of the genus Amphistegina and their symbiotic algae (diatoms) to elevated temperatures.

Together with Professor Albert Sickmann, bioanalyst at ISAS, and Professor Michal Kucera, micropaleontologist at MARUM - Center for Marine Environmental Sciences at the University of Bremen, the geoecologist adapted new proteomics analysis methods to foraminifera. Thus, for the first time, the team succeeded in breaking down the contributions of the unicellular organisms and their symbionts to the stress response.

“In the algal symbionts, we saw an increase in proteins that indicate the degradation of damaged cell components and cell death, while the proteins for photosynthesis declined – a clear sign that this process of energy production was no longer working," said Marleen Stuhr.

The host organism, on the other hand, appeared to be less susceptible, according to the scientist. "In the thermally stressed foraminifera, we were able to demonstrate a clear increase in the number of proteins required for cell repair, because the stressed symbionts damaged their host. The foraminifera, however, adapted to the new conditions, now increasingly drawing their energy from their energy stores and absorbing more substances from the surrounding environment.”

Co-author Professor Albert Sickmann from ISAS added: "Using physiological measurements, researchers have so far only to a limited extent been able to determine the molecular processes in foraminifera and assign the reaction to environmental stress to the host or symbiont. The microscopically small foraminifera also made it difficult to investigate individual proteins, since the host and symbionts could not be separated. The methods of proteomics can now provide us with entirely new insights."

In the laboratory, the team of researchers exposed the foraminifera to different temperatures for one month and then dissected the proteins of the organisms together with their symbionts into shorter sections (peptides). The quantity and mass of these components were determined by mass spectrometry. Marleen Stuhr and her colleagues created a database of all known gene and peptide sequences of foraminifera and their symbionts, in this case diatoms. By comparing the detected peptide masses with the database, they were able to determine which proteins were present and from which of the two symbiotic partners they originated. The signal intensity – the amount of peaks in the mass spectra – was used to determine the amount of the respective proteins and their changes compared to non-stressed organisms. Finally, the functions of the proteins and their relative changes in quantity were used to reconstruct the biological and cellular processes.

As a continuation of her work, Stuhr plans to transfer the proteomics approach also to corals. This would provide information on the cellular adaptations that take place in the coral, i.e. the host, and the zooxanthellae, the symbionts, in the event of environmental changes. “This would help us to understand which factors make some organisms more resistant to certain stress influences. This is important to better manage coral reefs in terms of their resilience," said the scientist.

Publication:
Marleen Stuhr, Bernhard Blank-Landeshammer, Claire E. Reymond, Laxmikanth Kollipara, Albert Sickmann, Michal Kucera & Hildegard Westphal “Disentangling thermal stress responses in a reef-calcifier and its photosymbionts by shotgun proteomics” (2018, online first), Scientific Reports, DOI: 10.1038/s41598-018-21875-z

Weitere Informationen:

http://www.nature.com/articles/s41598-018-21875-z

Andrea Daschner | idw - Informationsdienst Wissenschaft
Further information:
http://www.leibniz-zmt.de

Further reports about: Proteomics Tropenforschung ZMT corals foraminifera proteins stress response symbiotic algae

More articles from Life Sciences:

nachricht A novel synthetic antibody enables conditional “protein knockdown” in vertebrates
20.08.2018 | Technische Universität Dresden

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>