Ever heard of this ? colour experts?

[Leigh]

There was a reply to a letter in our Horse and Hound magazine (26th June) by Andrew Hemmings (Senior lecturer at The Royal Argricultural College)

It said that 'In very rare cases, a spontaneous DNA mutation in the testis can mean that a previously inactive cream gene becomes active. Thus an undiluted sire is able to father dilute offspring'

Anyone ever heard of this ?

[RiddleMeThis]

There was a reply to a letter in our Horse and Hound magazine (26th June) by Andrew Hemmings (Senior lecturer at The Royal Argricultural College)

It said that 'In very rare cases, a spontaneous DNA mutation in the testis can mean that a previously inactive cream gene becomes active. Thus an undiluted sire is able to father dilute offspring'

Anyone ever heard of this ?
Depends on what you mean by heard of it. I know of ZERO documented cases of that particular mutation happening after the cream gene mutated the first time. However mutations can and do occur.

Mutation (which is what he is talking about, but specifically related to cream) can happen and when they do odd things happen like a cream from a non cream parent, or a tobiano from two non tobiano parents.

So I have heard of it but I havent.

ETA:It also depends on how much he actually knows about cream and pearl. If he knows very little he could be confusing dark buckskins and smokey blacks as non cream, when they actually have cream. IF he doesnt know about pearl he could be thinking that a horse carrying only one copy of pearl (and thus not showing it) and passing it to an offspring and the other parent passing cream and creating a fake DD, as the horse that had pearl mutating to have cream, when its not the case at all.

So it depends.

[Penthilisea]

And don't forget that wild bay can crop up which lightens mane, tail and points, but is neither cream nor pearl.

[JB]

Could be Pearl. In its single form, it's nothing. In it'd double form, it can turn a chestnut into a strange shade of orange. In it's single form on top of a creme gene, it turns the horse into a "double dilute", aka looks Perlino/Cremello/Smoky Black, but there's 1 creme and 1 Pearl gene.

I also agree with the smoky black or dark sooty buckskin, or even a dark sooty palomino looking like a regular color, but popping out single dilutes here and there.

Having flaxen genes, creating a light flaxen chestnut, could make it look like he produced a palomino.

Leigh, I think it would be worth writing to that gentleman to find out more of what he's referring to :)

[aurum]

I think it is someone trying to explain how the dilution could hide under dark bay and black. In Europe they like to talk about mutation as soon as they cannot explain something. Hate that!

[Ambrey]

Of course mutations happen.

But who knows what this guy is talking about- if he has documented such a case, you'd think he'd have written a paper on it?

[RiddleMeThis]

And don't forget that wild bay can crop up which lightens mane, tail and points, but is neither cream nor pearl.Wild bay doesnt lighten the tail or mane. May add frosting but doesnt really lighten it. It also doesnt lighten the points, it minimizes the points so they dont come up to the ankles.

What you may be thinking of is silver, which does lighten points main and tail.

[acc]

I will wager that cream was simply an example. The idea of one particular sperm cell mutating to cause something the sire himself did not carry is a fact of life. It may not be "common" in our eyes, but it happens. One thing one has to realize is just how many things there are to mutate, so while we think we're not looking at a mutation because the color was a logical result, we can't possibly know what mutations lie within such as minuscule internal differences and such.

The same could be said for a black out of two chestnuts... while certainly not common (or even heard of for some)... it CAN happen if the right things occur.

ACC

[rcloisonne]

The same could be said for a black out of two chestnuts... while certainly not common (or even heard of for some)... it CAN happen if the right things occur.
Do you have a proven (as in DNA) example of this? And could you please explain exactly how could it happen?

[aurum]

There is a "black" stallion in Germany that is in fact the darkest chestnut that exists. He truly looks black only in the light and sunshine you can see that he is in fact a "black chestnut".

I do not dispute mutations but here in Europe they make a mutation out of every color thing they cannot explain and they cannot explain it because they have just not understood the basics.

[RiddleMeThis]

Do you have a proven (as in DNA) example of this? And could you please explain exactly how could it happen?
Example of that exact thing happening? Not yet. (I am answering for her because we have discussed this at length.) Hopefully maybe soon though. There is a foal who was born looking black (as in had a foal coat that looked like a black foal coat, not chestnut,) and still looks black but is now getting flaxen. We are trying to get them to test that foal.

As to how it could happen, well the gene mutate. Every color that isnt Bay dun, is a mutation. As to how exactly mutations occur, like the actual mechanics of it I will let her try and explain.

[acc]

This sort of explains some of it:
http://en.wikipedia.org/wiki/Mutation-selection_balance

Basically it is the reason for the survival of species. They don't adapt, they dont live. Or at least they didn't before human intervention. People tend to look at mutations like the X-Men frak mutants type of thing when it's really not like that at all. It's just one simple flip in one single sperm or eg cell from one alelle to another. For instance from cr to CR. EVERY horse has the cream location and thus has the ability to be a CR if the right switch is flipped. They have done research that shows that there is something like at least 4 individual mutations in every dog born (I'll ask the friend that showed this to me to find the study again). Of course most, if any, of these will not be visible, but they are there. Like RMT said, any horse that is not a bay dun has at least one mutation specifically color related. What about HYPP? What about Pearl? All mutations that happenned in our lifetimes. There is nothing to say the mutation couldn't have been to something we already knew about, like cream, or black.

If the world started out all red dirt and all horses were chestnut... for some reason the world start changing to all black dirt, horses wouldn't have much chance to survive unless they adapted. Whereas before the occasional black that was born did not survive, suddenly the reds start disappearing and the blacks start taking over.

Mutation = evolution. Evolution = mutation. And I will be the first to admit I am Christian and don't necessarily believe in what most people call "evolution"... but mutation is a fact of life.

Much credit to my husband who has a Ph.D in population genetics and equine reproduction & physiology as well as a Masters in... well I forget. He's a very well studied man. :-)

ACC

[Ambrey]

I think the question is: are there documented cases of spontaneous mutations occuring that activate an inactive cream gene, or deactivate a cream gene?

Or any other unexpected color combinations?

I don't think anyone doubts that it could happen in the wide world of genetics, just that there are other more likely explanations for sudden popping up of dilute horses in a gene pool. For example- dilute TBs, there has been quite a bit of speculation including a) that they have always been in the breed, but rare and people just didn't recognize them as dilutes and b) "accidental" influx of QH blood. I don't think people really suspect that a random mutation caused cream to suddenly exist in the TB, when there are other, more likely explanations.

[Leigh]

Thanks everyone :)

I'm sure he did mean cream not pearl...and I don't think he meant dark buckskins where the cream gene isn't obvious.

I just have never heard of horses without a cream gene in their DNA makeup suddenly mutating and throwing a dilute foal..not that I've had much experience as I've only recently understood the basics :)

Just wondered if anyone had heard of this or seen proof of this?

I may email the guy and ask him to explain..just hope he doesn't get 'too' technical as I won't be able to understand lol

[RiddleMeThis]

Only proof I can think of is the first dilute horse ever, for that particular mutation at least.