Genetic modification alters hair colour

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Genetic modification alters hair colour

http://www.newscientist.com/news/news.jsp?id=ns99992774

 

 

You are what your mother ate, suggests study

http://www.newscientist.com/news/news.jsp?id=ns99994017

 

 

 

22:00 09 September 02

 

NewScientist.com news service

 

Shuttling genes into hair follicles can alter hair colour, scientists have

shown for the first time. The experiments on mice also suggest genetic

modification treatments for hair loss will be possible in future.

 

Closer to reality is the prospect of restoring colour to greying hair. But

it will be some years before the pioneering work that has given mice shocks

of gaudy green hair reaches the salon.

 

" They're punk mice, you could say, " jokes Robert Hoffman, head of the team

which developed the mice with green hair at AntiCancer, a Californian

biotech company based in San Diego.

 

But he warns that the breakthrough is very much a first step, and that genes

to treat baldness cannot be delivered in the same way until someone

identifies them. Candidates include the genes that suppress the

overproduction of the " superandrogen " , dihydrotestosterone. This hormone is

also implicated in acne, which in theory could also be helped by the new

approach.

 

 

Skin slivers

 

 

The genes transferred into the mice's hair follicles make a fluorescent

protein from jellyfish, which glows green in blue light. To load the

jellyfish genes, Hoffman grew small sheets of mouse skin. After softening up

the tissue with an enzyme called collagenase, he dunked the skin slivers in

a solution containing an adenovirus similar to the one that causes colds.

 

The viruses had already been loaded with copies of the jellyfish gene.

Hoffman had also removed the genes that that enable the virus to replicate,

so that it would load its genetic cargo into mouse cells without replicating

itself.

 

Within hours, Hoffman peered down the microscope and could see blobs of the

green protein appearing in hair follicles, the sources of each new shaft of

hair. In the treated skin slivers, 80 per cent of the growing hairs were now

green.

 

And when he grafted the slivers onto mice lacking hair of their own, the

transplanted hair continued developing normally in every way, except that it

was green under blue light.

 

 

Pigment production

 

 

GM treatments to restore hair colour would need to increase the amount of

the pigment melanin. Changing hair colour would mean switching the form of

melanin produced. Black hair results from eumelanin, while red and brown

hair owe their hue to a lighter form, called pheomelanin.

 

 

But no-one yet knows the molecular secret of blonde hair. " It's one thing to

restore pigment formation to a greying follicle, but quite another to modify

the pigment, " says Hoffman. " So it's not yet a replacement for the peroxide

blonde. "

 

Once hair colour genes are discovered, it might be possible for people

treated with them to switch them on and off whenever they want with hair

creams that activate or turn off the genes.

 

Next, Hoffman plans experiments in albino mice. These lack the gene for

tyrosinase, an enzyme that regulates the production of melanin, to see if

pigment production can be restored by loading the missing gene.

 

Journal reference: Proceedings of the National Academy of Sciences (DOI:

/10.1073/pnas.192453799)

 

 

Andy Coghlan

 

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