Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Swiss Scientists Explain Evolution of Extreme Parasites

14.10.2014

Extreme adaptations of species often cause such significant changes that their evolutionary history is difficult to reconstruct.

Zoologists at the University of Basel in Switzerland have now discovered a new parasite species that represents the missing link between fungi and an extreme group of parasites. Researches are now able to understand for the first time the evolution of these parasites, causing disease in humans and animals. The study has been published in the latest issue of the scientific journal Proceedings of the National Academy of Sciences (PNAS).


The water flea (Daphnia magna) serves as the host of the newly described parasite. The animal measures about 4mm in length. Dieter Eber, University of Basel


Electronmicroscopic picture of the spores of the newly discovered microsporidium M. daphniae. The spores measure around 2 micrometer in length. Ronny Larsson

Parasites use their hosts to simplify their own lives. In order to do so, they evolved features that are so extreme that it is often impossible to compare them to other species. The evolution of these extreme adaptations is often impossible to reconstruct.

The research group lead by Prof. Dieter Ebert from the Department of Environmental Science at the University of Basel has now discovered the missing link that explains how this large group of extreme parasites, the microsporidia, has evolved. The team was supported in their efforts by scientists from Sweden and the U.S.

Microsporidia are a large group of extreme parasites that invade humans and animals and cost great damage for health care systems and in agriculture; over 1,200 species are known. They live inside their host's cells and have highly specialized features:

They are only able to reproduce inside the host's cells, they have the smallest known genome of all organisms with a cell nucleus (eukaryotes) and they posses no mitochondria of their own (the cell's power plant). In addition, they developed a specialized infection apparatus, the polar tube, which they use to insert themselves into the cells of their host. Due to their phenomenal high molecular evolution rate, genome analysis has so far been rather unsuccessful: Their great genomic divergence from all other known organisms further complicates the study of their evolutionary lineage.

Between fungi and parasite

The team of zoologists lead by Prof. Dieter Ebert has been studying the evolution of microsporidia for years. When they discovered a new parasite in water fleas a couple of years ago, they classified this undescribed species as a microsporidium, mostly because it possessed the unique harpoon-like infection apparatus (the polar-tube), one of the hallmarks of microsporidia.

The analysis of the entire genome had several surprises in store for them: The genome resembles more that of a fungi than a microsporidium and, in addition, also has a mitochondrial genome. The new species, now named Mitosporidium daphniae, thus represents the missing link between fungi and microsporidia.

With the help of scientists in Sweden and the U.S., the Basel researchers rewrote the evolutionary history of microsporidia. First, they showed that the new species derives from the ancestors of all known microsporidians and further, that the microsporidians derive from the most ancient fungi; thus its exact place in the tree of life has finally been found.

Further research confirms that the new species does in fact have a microsporidic, intracellular and parasitic lifestyle, but that its genome is rather atypical for a microsporidium. It resembles much more the genome of their fungal ancestors.

Genome modifications
The scientists thus conclude that the microsporidia adopted intracellular parasitism first and only later changed their genome significantly. These genetic adaptations include the loss of mitochondria, as well as extreme metabolic and genomic simplification. “Our results are not only a milestone for the research on microsporidia, but they are also of great interest to the study of parasite-specific adaptations in evolution in general”, explains Ebert the findings.

Original source
Haag, K.L., James, T.Y., Pombert, J.-F., Larsson, R., Schaer, T.M.M., Refardt, D. & Ebert, D. 2014.
Evolution of a morphological novelty occurred before genome compaction in a lineage of extreme parasites
Proceedings of the National Academy of Sciences, USA, 13. Oktober 2014) www.pnas.org/cgi/doi/10.1073/pnas.1410442111

Further information
Prof. Dieter Ebert, Department for Environmental Science, Zoological Institute, phone: +41 (0)61 267 03 60, fax +41 (0)61 267 03 60, email: dieter.ebert@unibas.ch

Olivia Poisson | Universität Basel
Further information:
http://www.unibas.ch

Further reports about: Department Environmental Evolution Sciences ancestors discovered fungi genomic new species parasite parasites species

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>