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Questions tagged [melanin]

Biopigment, present in the skin and hair of humans.

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What part of the skin is damaged under sun exposure?

How exactly does extensive sun exposure lead to skin damage and increase cancer risk. In which part of the skin is the sun doing the most damage. Is it in the epidermis or beneath ? I would like to ...
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Could being exposed to excess UV in the arctic lead to a human eye color change? If so, what is the mechanism?

The CBS News article Expedition Antarctica: A father and son's journey to save the planet says (in part): Thirty-two years ago, Robert Swan made history as the first person to walk to both poles. ...
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Why does the scalp hair become grey first?

I understand that when the hair follicles produce less melanin or stop producing melanin altogether, hair becomes grey. But it seems like it is the scalp hair that becomes grey first. If follicles are ...
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1answer
1k views

Can cysteine alone change pigmentation?

According to this graph (from here): cysteine contributes to pheomelanogenesis, and having a high enough concentration of cysteine makes the shift towards pheomelanin instead of eumelanin. So my ...
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Why is black eumelanin black even though it consists of black AND brown molecules?

In dogs,eumelanin consists of molecules of DHI and DHICA. DHI and DHICA are made from dopachrome. DHI through DHI oxidase and DHICA through DHICA oxidase also known as TYRP1. When TYRP1 has a mutation ...
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1answer
929 views

What decides between the synthesis of eumelanin and pheomelanin on a biochemical level?

MC1R is a very well known gene where a loss-of-function mutation will cause the synthesis of pale/redish pheomelanin instead of black/brown eumelanin. MC1R is only a receptor which doesn't directly ...
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1answer
192 views

How does TYRP1 affect the synthesis of black and brown eumelanin (on a biochemical level)?

TYRP1 (aka B-locus) is a gene in dogs that determines whether black or brown eumelanin is produced (assuming eumelanin is produced at all which is determined by the MC1R gene). I've looked at many ...
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1answer
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How to increase pheomelanin production?

How can you increase the pheomelanin production in your body, while decreasing the eumelanin production? In other words, shifting the balance towards pheomelanin. From what I see, sulfur and cysteine ...
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1answer
1k views

Why is hyper pigmentation the common aftermath of skin lesions and abrasions?

I'm aware that melanocytes produce melanin, giving color to the skin, but why are these cells recruited or overactive when healing skin abrasions, lesions and sores when T-cells and inflammatory ...
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1answer
4k views

How long does a tan last?

How long do melanocytes and melanosomes continue to protect DNA after UV exposure? Basically, if skin is tanned, then over the next month it is shed, will melanocytes continue to produce high levels ...
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566 views

Why Do Most Humans & Cats Have Blue/Bluish Eyes At Birth?

I've read that the eye color at birth for most humans and for cats may not always be the the true genetic color at first. This is due to the lack of melanin in the iris. This makes sense as there is ...