Skip to main content

Due to decreasing use over the years, I have decided to disable the forum functionality of the site.

Forums will still be available to view but new posts are no longer allowed.

'Chestnut gene'/MC1r mutation

Do you think its an old very widespread gene or does it spontaneously mutate fairly readily? It occurs on Icelandics which have had a closed stud for over 1000 years, also occurs in breeds not normally thought of as chestnut- Friesians, Fjords, etc. and has been noted in Przewalski's horses. Has anyone come across an anomalous occurrance of the gene? I know its recessive so can stay hidden forever, but might it just happen from scratch now and again or are all chestnuts descended from the same single horse? How long ago might that have been? Join me in my musings :ymdaydream:

accphotography Sat, 04/04/2009 - 15:06

It doesn't mutate on a regular basis by any means. Only two mutations of it have ever been found in ANY breed and one of those is VERY rare from what I hear. As far as I am aware of, every red horse in any breed (and any heterozygote) carries the same mutation (or the other, rare, one). Now if you mean any given foal having a mutation (aka, but parents were homozygous black but the foal ends up with a red allele), that I couldn't tell you as I doubt it would be documented. A population geneticist might be able to give you something more on that.

I'm told it is believed all horses started as bay dun and mutated from there so it's pretty logical to think the red mutation happened early on and that all red alleles trace to that one horse (probably as far back as Adam & Eve :laugh1 ). Since it's that old and we're only aware of two mutations causing red, it seems pretty clear that it's not a gene that readily mutates (except for possibly a flip from black to red, but it would still test to the same allele).

Morgan Sat, 04/04/2009 - 16:19

I'm pretty sure its old for that same reasoning.
Not quite Adam and Eve though :lol: otherwise I expect there would be more red donkeys and zebras. I think it probably happened early in [i]domestic[/i] horses and spread after that when people said "oooh pretty red!".

vneerland Sat, 04/04/2009 - 21:49

[quote="Morgan"] otherwise I expect there would be more red donkeys and zebras. I think it probably happened early in [i]domestic[/i] horses and spread after that when people said "oooh pretty red!".[/quote]

Didn't we have some pictures on the old forum of zebras gone. Uh. Was it red? Or just different? :?

CMhorses Sun, 04/05/2009 - 02:20

Probably more like ivory in donkeys, appeared to be a rare recessive gene.
http://www.animalorphanagekenya.org/pho…" onclick="window.open(this.href);return false;
Wow, on the website it said that the wild 'white' zebras had been poached to 4 and then they sent out people to capture them, but when they found them two had already been killed and they managed to capture the other two. They were an old mare and a young stallion, which they used to breed their own herd, which reached 81 in 2004. Also said that the wild white zebras never exceeded 8 when it was recorded and protected.

CMhorses Mon, 04/06/2009 - 15:34

I sent an email to the preserve asking what color eyes the zebras have and they did not send me a picture but said that they are very pale almost pink. I found that very interesting, to me it makes it seem more similar to champagne, but we really can't compare it to anything in horses or donkeys.

accphotography Mon, 04/06/2009 - 22:51

I'm told it's technically albino. Since cream (MATP) is considered an albino (or albino related) gene it makes sense those zebras could be cream and/or albino.