The phenomenon of light emission by living organisms, bioluminescence, is quite common, especially in marine species. It is known that light is generated by chemical reactions in which oxygen molecules play an important part.
In the animal world, these chemical reactions take place in special luminescent cells called photocytes. These are aggregated into complex light organs, in which the intensity of light is regulated by nerve impulses, and in which light can be modulated with the help of reflectors, lenses and filters. By these means, organisms can adjust the wavelength, diffusion and intensity of light according to need. But the exact mechanisms behind these processes remain shrouded in mystery.
Jenny Krönström, a researcher at the Department of Zoology of the University of Gothenburg has put another piece of the jigsaw puzzle in place by investigating the light organs of marine jellyfish, crustaceans and fish. In her thesis she reveals that krill, the luminescent crustacean, is equipped with special muscles that regulate light intensity through contraction and relaxation.
Nitric oxide is also thought to play an important role in the bioluminescence of krill. It is produced in the small capillary vessels that keep the krill's photocytes supplied with oxygen, as well as in special closure muscles, sphincters, that are located at the point where these capillaries distribute blood to the photocytes. Experiments with agents that make the sphincters contract or relax show that when the sphincters relax, the krill begins to luminesce, presumably because of the increased flow of oxygenated blood to the photocytes.
As bioluminescence has developed independently at several different points in evolution, different species have developed different methods of regulating and emitting light. Jenny Krönström's research demonstrates that nitric oxide also has different effects in different species. In the remarkable deep sea Silver Hatchetfish (Argyropelecus olfersii) nitric oxide inhibits the light reaction, whilst in the Plain Midshipman fish (Porichthys notatus) it has an opposite, stimulating effect.
Biological light is not only useful to the organism itself as a biological torch, camouflage or as a means of communication; the substances that are involved in the chemical luminescent reaction have also shown themselves to be useful in modern molecular biology, in which the discovery of green fluorescent protein, which produces green light in jellyfish, led to the Nobel Prize in Chemistry as recently as 2008.
The thesis "Control of bioluminescence: Operating the light switch in photophores from marine animals" was defended on February 20th 2009.
Images: The Silver Hatchetfish (Argyropelecus olfersii) and "light-switch" muscles of the luminescent krill.For further information, please contact:
Krister Svahn | idw
Further reports about: > Argyropelecus > Argyropelecus olfersii > Hatchetfish > Plain Midshipman fish > Porichthys notatus > Silver Hatchetfish > Zoology > bioluminescence > chemical reaction > chemical reactions > fluorescent protein > living organisms > luminescent crustacean > marine animals > marine jellyfish > marine luminescence > marine species > nerve impulses > nitric oxide > oxygen molecules > phenomenon of light emission > photocytes
Flavins keep a handy helper in their pocket
25.04.2018 | University of Freiburg
Complete skin regeneration system of fish unraveled
24.04.2018 | Tokyo Institute of Technology
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology