Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Reviving 100-year-old resting spores of diatoms

01.03.2011
Diatoms account for a large proportion of the phytoplankton found in the water, and live both in the open sea and in freshwater lakes. By reviving 100-year-old spores that had laid buried and inactive in bottom sediment, researchers at the University of Gothenburg, Sweden, have shown that diatoms are also genetically stable and survival artists.

Recent research has shown that diatoms exhibit great genetic differences and that they occur in discrete populations, which means that they multiply sexually to a greater extent than previously believed. What makes diatoms special is that if the environment they live in becomes too inhospitable they form resting spores, which gather in sediment at the bottom of the sea. When conditions improve, the spores can be revived.

The study concerned is based on a sample of sediment from a highly eutrophic Danish fjord on the east coast of Jutland, Mariager Fjord, whose anoxic bottoms and bottom sediments today do not show any signs of life. After dating the different layers of a sediment core, the researchers took small pieces of sediment from various depths and transferred them to an environment favourable to diatoms. This enabled them to revive resting spores.

”We revived hundreds of genetic individuals of diatoms and induced them to start dividing again and to form cloned cultures. The oldest are more than 100 years old, the youngest quite fresh. We then identified the revived individuals genetically," says Anna Godhe of the Department of Marine Ecology at the University of Gothenburg.

40 000 generations of diatoms
As diatoms normally divide once a day, this means that for a diatom a period of 100 years is equivalent to 40 000 generations. In human terms, this means genetic material equivalent to around 800 000 years.

”We found certain differences between the algae that went into a state of rest at the start of the 20th century compared with those that formed resting spores when the eutrophication was at its worst and the freshest ones of all, but the individuals are for the most part very homogeneous throughout the sediment core, that’s to say 40 000 generations of diatoms.”

No traces of genetic impact over 100 years
”The most exciting thing of all in the whole study is that there are no traces at all of genetic impact from the open sea population on the diatoms in Mariager Fjord during the 100 years we have studied, despite a constant influx of diatoms from the Kattegatt with the surface water. Not one out of all the millions upon millions of diatoms that have found their way into the fjord from the Kattegatt has become established and continued to grow in the fjord.
The researchers believe that this is due to the fact that the algae that live inside the fjord are so superbly well adapted to the fjord environment and that there are so many of them (millions per litre of water, thousands per gram of sediment) that colonisers from outside are rapidly out-competed.

The article Hundred years of genetic structure in a sediment revived diatom population has been published in the scientific journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). The study has been conducted by Karolina Härnström and Anna Godhe at the University of Gothenburg in cooperation with Marianne Ellegaard and Thorbjørn J. Andersen at Copenhagen University.

Contact:
Anna Godhe, Department of Marine Ecology, University of Gothenburg
+46 (0)31 786 2709
anna.godhe@marecol.gu.se
Karolina Härnström, Department of Marine Ecology, University of Gothenburg
+46 (0)73 043 9247
karolinaharnstrom@gmail.com

Helena Aaberg | idw
Further information:
http://www.gu.se
http://ub016008.ub.gu.se/cgi-bin/auth.cgi?url=http://www.pnas.org/content/early/2011/01/27/1013528108.full.pdf+html?sid=8290eb67

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>