More than 20% of the filets of Atlantic salmon may have unattractive black and red spots, which are often >1 cm and create substantial financial losses. The spots are far more abundant in reared than in wild salmon, and their ...
Molecular & Computational biology
Jan 8, 2024
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322
When most people think of colour change, they think of octopuses or chameleons – but the ability to rapidly change colour is surprisingly widespread.
Plants & Animals
May 3, 2013
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2
Melanin is best known as the pigment that dictates our skin tones, but it is found just about everywhere—in our brains, in our hair. It is even found in cuttlefish. But as abundant as melanin is, its exact macromolecular ...
Materials Science
May 17, 2016
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1951
(PhysOrg.com) -- Deciphering microscopic clues hidden within fossils, scientists have uncovered the vibrant colors that adorned a feathered dinosaur extinct for 150 million years, a Yale University-led research team reports ...
Archaeology
Feb 4, 2010
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0
Chemists, materials scientists and nanoengineers at UC San Diego have created what may be the ultimate natural sunscreen.
Nanomaterials
May 17, 2017
2
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Scientists from Virginia Tech and the University of Bristol have revealed how pigment can be detected in mammal fossils, a discovery that may end the guesswork in determining the colors of extinct species.
Paleontology & Fossils
Sep 28, 2015
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712
(Phys.org) -- Melanin – the pigment that colours skin, eyes and hair – could soon be the face of a new generation of biologically friendly electronic devices used in applications such as medical sensors and tissue ...
Condensed Matter
Jun 27, 2012
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2
A small team of team of biologists affiliated with several institutions in Argentina has found an instance of melanism in a wild gentoo penguin living in Antarctica. In their paper published in the journal Polar Biology, ...
(Phys.org) —A team of chemical researchers at the University of Melbourne in Australia has discovered a simple coating technique that uses nothing but tannic acid and iron ions. In their paper published in the journal Science, ...
The popular idea that Northern Europeans developed light skin to absorb more UV light so they could make more vitamin D – vital for healthy bones and immune function – is questioned by UC San Francisco researchers in ...
Evolution
Jun 30, 2014
17
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Melanin i/ˈmɛlənɪn/ (Greek: μέλας, black) is a pigment that is ubiquitous in nature, being found in most organisms (spiders are one of the few groups in which it has not been detected). In animals melanin pigments are derivatives of the amino acid tyrosine. The most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, and their reduced forms. All melanins can be considered as derivatives of polyacetylene, since they rely on a polyconiugate structure. Another common form of melanin is pheomelanin, a red-brown polymer of benzothiazine units largely responsible for red hair and freckles. The presence of melanin in the archaea and bacteria kingdoms is an issue of ongoing debate among researchers in the field.
The increased production of melanin in human skin is called melanogenesis. Production of melanin is stimulated by DNA damage induced by UVB-radiation, and it leads to a delayed development of a tan. This melanogenesis-based tan takes more time to develop, but it is long-lasting.
The photochemical properties of melanin make it an excellent photoprotectant. It absorbs harmful UV-radiation (ultraviolet) and transforms the energy into harmless heat through a process called "ultrafast internal conversion". This property enables melanin to dissipate more than 99.9% of the absorbed UV radiation as heat (see photoprotection). This prevents the indirect DNA damage that is responsible for the formation of malignant melanoma and other skin cancers.
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