Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Indispensable Guests: Shedding Light on Past Life

07.12.2012
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
E-Mail: stefan.rensing@biologie.uni-marburg.de

Professor Dr. Uwe Maier,
Fachgebiet Zellbiologie und „LOEWE-Zentrum für Synthetische Mikrobiologie (SYNMIKRO)“
Tel.: 06421/28-21543
E-Mail: maier@biologie.uni-marburg.de

Johannes Scholten | idw
Further information:
http://www.uni-marburg.de

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 >>>