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17 December 2014

Deforestation threatens species richness in streams ...

05 December 2014

Unsichtbare Arten - Bedrohte Arten sind in Verbreitungsmodellen unterrepräsentiert...

02 December 2014

Von der Forschung in die Praxis: „Algenmelder“ für Gewässer...

12 November 2014

On a safari through the genome – genes offer new insights into the distribution of giraffes...

31 October 2014

Frankfurter Biodiversität und Klima Forschungszentrum (BiK-F) erhält Spitzenbewertung vom Wissenschaftsrat ...

23 October 2014

Vortrag „Long term dynamics in the Serengeti Ecosystem: Lessons for Conservation and Society “ ...

25 September 2014

Dengue fever and malaria in the Himalayas...

18 September 2014

Vorratshaltung beim Tannenhäher: Samenverstecke nutzen dem "gefiederten Förster" mehr als den Bäumen...

15 September 2014

The Biodiversity and Climate Research Centre opens its doors to the public...

11 September 2014

Pesticides are more toxic for soil organisms in dry soil and at enhanced temperatures ...

01 September 2014

Vortrag 4. September „The Climate Change Challenge and Opportunities“ ...

01 August 2014

More People Means More Plant Growth, NASA Data Show ...

25 July 2014

Erstmals Sandmücke in Hessen entdeckt...

09 July 2014

Climate change: Tropical species are most vulnerable to rising temperatures...

25 June 2014

Vogelschutz lohnt sich! – Vogelbestände in Osteuropa profitieren von neuer Gesetzgebung...

18 June 2014

Spanish slug – busting an invasion myth...

17 June 2014

The hidden history of rain: plant waxes reveal rainfall changes during the last 24,000 years...

11 June 2014

It’s complicated - new insights into the evolutionary history of bears ...

12 May 2014

A tale of survival – scientists reveals how fish were able to colonise poisonous springs...

08 May 2014

New ways for understanding the link between the uplift of the Tibetan Plateau and species diversity...

29 April 2014

Gehen oder bleiben? – Neue Emmy Noether-Gruppe erforscht die Klima-Anpassung von Vögeln ...

08 April 2014

Mapping ecosystem services: New method shows seed dispersal pathways of hornbills...

26 March 2014

Study yields 'Genghis Khan' of brown bears, and brown and polar bear evolution...

18 March 2014

Ants plant tomorrow's rainforest...

04 March 2014

Allergikern blüht etwas: Erhöhte Fitness der Beifußambrosie in Europa nachgewiesen ...

12 February 2014

Zukunftsthema Infektionskrankheiten – zwei neue Forschungsprojekte im Bereich Medizinische Biodiversität und Parasitologie...

05 February 2014

Aquatic Insects – a tremendous potential for research on diversification...

05 February 2014

Coffee: More biodiversity, better harvest ...

20 January 2014

Erfolgreiche Renaturierung von Gewässern: Das biologische Umfeld ist entscheidend...

Press Releases

A tale of survival – scientists reveals how fish were able to colonise poisonous springs

Frankfurt am Main, Germany, May 12, 2014. Hydrogen sulphide (H2S) is a potent inhibitor of aerobic respiration. However populations of shortfin molly fish managed to colonise springs with high concentrations of dissolved hydrogen sulphide. In a new study researchers from LOEWE Biodiversity and Climate Research Centre (BiK-F) and the Goethe University Frankfurt am Main present evidence of genetic changes minimizing the harmful effects of H2S which enable the fish to survive in this deleterious environment. The study provides insight into the molecular mechanisms of this key adaptation for the first time. It is published online today in "Nature Communications".

Shortfin molly fishes (Poecilia mexicana) may only measure a few inches, but they are still exceptional. Populations of Poecilia mexicana, whose relatives are the well-known guppy, colonised sulphide-rich volcanic springs in Southern Mexico. In making this particular habitat their home, they have made the impossible possible, because hydrogen sulphide (H2S), as for many other animal, is lethal. Even at low concentrations the gas blocks the cytochrome c oxidase-complex (COX). The higher the level of hydrogen sulphide, the more the activity of COX is inhibited. As it is essential for respiration, this turns out to be lethal in the end.

Changes in genetic make-up make less susceptible to poison
A team led by Prof. Dr. Markus Pfenninger, LOEWE Biodiversity and Climate Research Centre (BiK-F) and PD Dr. Martin Plath, Goethe University, has taken a closer look at the survivors. Their analysis showed that the COX activity of individuals of shortfin molly fish which colonise H2S-rich waters remains virtually unchanged under high H2S concentrations. This is due to a number of changes in the cox1 and cox3 genes, which have only occurred in populations living in the poisonous springs. Thus, transplanting individuals from non-sulphidic habitat to springs with high H2S levels kills them for sure.

Molecular mechanisms of adaptation to extreme habitat
"In this paper we analyse the key adaptation to an extreme habitat up to its molecular basis at the level of amino acids. This way, for the first time, we are able to point out, where exactly the adaption has taken place." Pfenninger concludes. The team also modelled three dimensional protein structures in order to shed light on necessary significant structural changes of amino acids in the cox1 gene. Without these structural changes, the colonisation of the H2S-containing water for the fish would have been impossible. By colonising the poisonous springs, where there are hardly any other competitors, the fish may feed on resistant midge larvae that also occur there.

Closely related fish follow different paths to adaptation
The study also shows that closely related populations of a species follow parallel as well as disparate paths in response to similar environmental conditions. Three shortfin molly fish populations were sampled for study. Two of the populations show the same changes in their genetic material in adapting to the hostile conditions. However this proved to be not the case for the third population of shortfin molly fish. Whereas these fish also tolerate high levels hydrogen sulphide, the mechanism enabling their adaptation is still subject to ongoing research.

Paper:
Pfenninger, M. et al.: Parallel evolution of cox-genes in H2S- tolerant fish as key adaptation to a toxic environment – Nature Communications, DOI: 10.1038/ncomms4873

Press images:

Atlantik-Kaerpfling

Poecilia mexicana @M.Pfenninger, [Download in 300 dpi]

Terms of use:  Images may be used for editorial purposes only. Please state the copyright information as given in the image caption. Use of images for commercial purposes prohibited..

For more information please contact:
Prof. Dr. Markus Pfenninger
Goethe University &
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Tel. +49 (0)69 7542 1841
Pfenninger@bio.uni-frankfurt.de

or

Sabine Wendler
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Press officer
Tel. +49 (0)69 7542 1838
Sabine.wendler@senckenberg.de

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