Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Indispensable Guests: Shedding Light on Past Life

Let there be light: An international consortium including a team from Marburg has analyzed a genome of algae whose cells contain the remains of foreign species that the host organisms use to generate energy by way of photosynthesis.
The hosts haven’t transferred all of their permanent guests’ genetic material into their nuclei, because genetic information could have become lost in the process, as the scientists assume. Their results appear in the current issue of the journal Nature from Thursday, 6 December 2012.

“For the first time, we have sequenced the nuclear genomes of two unicellular algae that are remarkable in their genetic and cellular complexity,” write the authors, among whom are Professor Dr. Stefan Rensing, Professor Dr. Uwe Maier, Dr. Franziska Hempel, Aikaterini Symeonidi, and Dr. Stefan Zauner from the University of Marburg. Cells contain a variety of so-called organelles – subcellular components that fulfill critical functions for the cell, such as energy conversion or photosynthesis. These organelles originated from previously discrete cells that were integrated into the cell in the distant past by the ancestors of the host organism.
Usually organelles were converted from bacteria, but not so in the case of several species of algae: They learned photosynthesis by absorbing other plant cells, including all of their existing organelles, the so-called chloroplasts. The term for this process is secondary endosymbiosis: By continuing to take advantage of the services of their new workers, the hosts can use sunlight to produce nutrients.

Structures that do not serve this purpose are usually lost in the course of evolution. In a few rare cases, however, the symbiotic organelles still contain nuclei of greatly reduced dimensions that stem from the original organism – for instance in cryptophytes and chlorarachniophytes.
Why does the nucleus remain intact in these species? In order to find out, the international research consortium first determined which sequences the four nuclear genomes of two relevant species possess. The result: Both of the residual nuclei contained only a fraction of the genes possessed by independently living related species. As the authors report, much of the remaining genetic information does not exhibit any similarity at all to that of known genes. Nevertheless, they control vitally important processes that occur in these organelles, such as translation, i.e., the conversion of genetic information into proteins.

A sizable quantity of genes evidently wandered from the organelles acquired by way of secondary endosymbiosis into the nucleus of the host. The scientists refer to the result as a “a complex mosaic of genes whose evolutionary histories do not reliably predict where their protein products function within the cell.”
Uwe Maier is a member of “LOEWE – Center for Synthetic Microbiology” of the University of Marburg. Among other things, he and his team in Marburg prepared sequencing data for the project. In addition, they identified encoded proteins and determined their location. Stefan Rensing’s research group at the Cluster of Excellence “BIOSS Centre for Biological Signalling Studies” of the University of Freiburg helped to identify the proteins that are imported into the organelles and analyzed contaminations, duplication events, and all of the proteins involved in the regulation of the transcription.
(Translation: University of Freiburg)

Original Publication: Bruce A. Curtis & al.: Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs, Nature (6.12.2012), DOI: 10.1038/nature11681
Further Information:

Professor Dr. Stefan Rensing,
Fachgebiet Zellbiologie

Professor Dr. Uwe Maier,
Fachgebiet Zellbiologie und „LOEWE-Zentrum für Synthetische Mikrobiologie (SYNMIKRO)“
Tel.: 06421/28-21543

Johannes Scholten | idw
Further information:

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>