Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Heidelberg Researchers Create Three-dimensional Model of Bacterium

15.08.2013
New methods of electron microscopy decode the structure of Gemmata obscuriglobus

Certain bacteria can build such complex membrane structures that, in terms of complexity and dynamics, look like eukaryotes, i.e., organisms with a distinct membrane-bound nucleus. Scientists from Heidelberg University and the European Molecular Biology Laboratory (EMBL) made this discovery employing new methods in electron microscopy.

The research team succeeded in building a three-dimensional model of the Gemmata obscuriglobus bacterium, including the structure of its membrane system. Their studies proved, however, that the G. obscuriglobus does not have a “true” nucleus. Despite this outlier characteristic, it remains classified as a bacterium and thus a so-called prokaryote. The results of their research were published in “PloS Biology”.

“Since the beginning of microscopy, cells of living organisms have been classified into one of two categories,” explains Dr. Damien Devos, a researcher at the Centre for Organismal Studies (COS) at Heidelberg University. Eukaryotes “pack” their genetic material, their DNA, in an area enclosed in a membrane, the nucleus. Prokaryotes, however, which also include bacteria, do not have that type of cell nucleus. Several years ago, analyses using new techniques of two-dimensional imaging had suggested that the genetic material of G. obscuriglobus was surrounded by a double membrane – this and other unique characteristics of membrane structure called into question the differentiation between prokaryotes and eukaryotes.

“The possibility that a bacterium could have a structure similar to a cell nucleus threatened to unhinge one of the central assumptions of biology on which countless other analyses and interpretations were based,” explains Damien Devos. To study the unique features of the membrane structure in the G. obscuriglobus more closely, the Heidelberg researchers divided the bacterium into thin slices and examined them using an electron microscope. The slices were used to detect the membranes, track their course throughout the entire bacterium and reconstruct their organisation on the computer. This created a virtual model of G. obscuriglobus, which enabled the researchers to visualise the membrane organisation in three-dimensional space and analyse how the membranes were structured within the cell.

The studies demonstrated that the membranes within the G. obscuriglobus are only one part of the interior membrane that is present in all bacteria and that surrounds the cytoplasm. “G. obscuriglobus also evidenced additional characteristics that are found in other bacteria,” explains Damien Devos. According to the researcher, these results disprove the assumption of the existence of a bacterial cell nucleus. “The cell structure and the membranes of the Gemmata obscuriglobus are simply more complex than in ‘classic’ bacteria. Therefore, G. obscuriglobus does not constitute a new, separate group of organisms, and it cannot be classified a eukaryote,” says Dr. Devos, who collaborated with Rachel Santarella-Mellwig of the European Molecular Biology Laboratory.

Film material on the Internet: http://www.bork.embl.de/~devos/project/apache/htdocs/plancto/g3d/

Other information on the Internet: http://www.cos.uni-heidelberg.de/index.php/j.wittbrodt/d.devos

Original publication:
Santarella-Mellwig R, Pruggnaller S, Roos N, Mattaj IW, Devos DP (2013) Three-Dimensional Reconstruction of Bacteria with a Complex Endomembrane System. PLoS Biol 11(5): e1001565. doi:10.1371/journal.pbio.1001565
Contact:
Dr. Damien Devos
Centre for Organismal Studies (COS)
Phone +49 6221 54-6254
devos@cos.uni-heidelberg.de
Communications and Marketing
Press Office
phone: +49 6221 542311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.uni-heidelberg.de

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>