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.
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
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
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Tel. +49 (0)69 7542 1838
LOEWE Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
With the objective of analysis the complex interactions between biodiversity and climate through a wide range of methods, the Biodiversität und Klima Forschungszentrum [Biodiversity and Climate Research Centre] (BiK‐F) has been funded since 2008 within the context of the Landes‐ Offensive zur Entwicklung Wissenschaftlichökonomischer Exzellenz (LOEWE) of the Land of Hessen. The Senckenberg Gesellschaft für Naturforschung and Goethe University in Frankfurt as well as other, directly involved partners, co‐operate closely with regional, national and international institutions in the fields of science, resource and environmental management, in order to develop projections for the future and scientific recommendations for sustainable action.
For further details, please visit www.bik‐f.de
Sabine Wendler | Senckenberg
Unexpected flexibility found in odorant molecules
27.06.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie
Newly-discovered signal in the cell sets protein pathways to mitochondria
27.06.2016 | Eberhard Karls Universität Tübingen
High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!
In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...
Strands of cow cartilage substitute for ink in a 3D bioprinting process that may one day create cartilage patches for worn out joints, according to a team of engineers. "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches," said Ibrahim T. Ozbolat, associate professor of engineering science and mechanics. "Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."
Cartilage is a good tissue to target for scale-up bioprinting because it is made up of only one cell type and has no blood vessels within the tissue. It is...
Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.
Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...
A year and a half on the outer wall of the International Space Station ISS in altitude of 400 kilometers is a real challenge. Whether a primordial bacterium...
Researchers at Case Western Reserve University have developed a way to swiftly and precisely control electron spins at room temperature.
09.06.2016 | Event News
24.05.2016 | Event News
20.05.2016 | Event News
27.06.2016 | Agricultural and Forestry Science
27.06.2016 | Physics and Astronomy
27.06.2016 | Life Sciences