Dilute genes - cream, silver dapple, dun, champagne and pearl

[chev]

As Nicole said, there are four known dilute genes in horse coat colours. Some more about the way they work her....

First, the cream gene. Cream is responsible for turning chestnut to palomino, bay to buckskin, and less common colours such as cremello and perlino.

Cream is known as an 'incomplete dominant' - which means that if a horse has one copy of the gene, the coat is diluted, and two copies means it's diluted further. A bit like adding cream to coffee - and some, it gets pale. Add more, it gets paler still.

The gene works primarily on red pigment - if a horse carries two copies some effect will be seen on black, but a black with one cream gene often shows no real sign he's carrying it.

Chestnut with one cream gene gives palomino. These horses have a pale gold body colour and white or creamy white mane and tail. They have dark eyes and dark skin.

Chestnut with two cream genes gives cremello. This causes the eyes to be blue, the skin to be pink, an dbody and mane hair is a very pale cream - these horses can be so pale they're almost whit. Body colour will have a definite cream or off-white tinge if you look closely. This is the reason that palomino is a colour and not a breed - palominos will not breed true.

That means that breeding two palominos together gives a 50% chance of another palomino, a 25% chance of cremello, and a 25% chance of chestnut. Think of any breed - put a Welsh ppony on a Welsh pony, and you'll get another Welsh pony every time.... a breed breeds true. Palominos don't.

Bay with one cream gene gives buckskin. This colour is similar in some ways to golden dun - golden colour body with black mane tail and legs. There are important differences though - the body of a buckskin will be golden, whereas the golden dun tends to be a more faded shade. The legs of a pony with dun won't be truly black - just darker. A buckskin has black points. Duns usually have a dorsal stripe - this can occur in other colours, including buckskin, but in a dun will be absolutely sharp, while other colours tend to have a blurry line that 'leaks' into coat colour. Duns also tend to have a darker mask on the face and upper legs, which a buckskin doesn't. Duns often have zebra striping - buckskins usually don't.

Bay with two cream genes gives a shade known as perlino - here the black points are faded too. Perlinos have the same pale cream body colour that cremellos do, but they have a darker shade of mane and tail - the hair here remains a darker, slightly orangey shade.

Black with one cream gene is known as smokey black - often they appear to be black, and the existence of their cream gene is known only when they inexplicably produce a palomino foal when put to a chestnut.

Black with two cream genes is known as smokey cream - these horses are really indistinguishable from cremellos and perlinos, and virtually impossible to identify.

Pic shows a palomino. Although his baby coat is very pale, there is no way he could be cremello - his eyes are dark, his skin is dark, and the darker colour round his muzzle and legs shows the colour he will most likely end up.

[chev]

And onto dun....

Dun is a simple dominant - that means if a horse has dun, it'll be dun - and the shade will be the same reagrdless of whether it has one copy of dun or two.

Dun differs from cream in that it dilutes both red and black pigment equally, where cream will dilute only red if a horse has one gene, and both black and red if a horse has two.

Dun is known as an 'atavistic' colour - this means that if horse are left to breed among themselves, without human interference, they will, over generations, gradually develop dun colouring.

Dun has several characteristics, some of which were toughed on in the 'cream' post. I'll relist them here.

Duns always have diluted body colour, a little like horses with cream.

Duns usually have a dorsal stripe.

Duns often have zebra markings on the legs, and a darker 'mask' of colour on the face - may also show 'cobwebbing' on the face too.

The ears often have a fawn colour inside, and dark tips.

They also often have a lighter colour 'lining' the mane and tail - a two-tone mane and tail (often seen in Highlnds, and in Fjords).

Dun on chestnut - red dun, has darker chestnut mane, tail and legs, and diluted body colour

Dun on bay gives bay dun, or yellow or buckskin dun. Legs will be darker, but not black as in a bay with cream, and the body colour is less 'brilliant' - a aby dun has a very red dilute body, a buckskin dun more yellowy colour.

Dun on black gives grulla, or grullo - also known as mouse dun, the body colour is a shade of grey-brown with darker points. Depending on other modifiers (such as sooty) the colour can vary from a silvery grey through to a dark chocolate.

[Wally]

Ljóssie, known in Germany and Iceland as Isabelle, pale yellow dun. He has a distinct stripe and zebra markings, often mistaken for Palomino.

[chev]

Champagne is a dilute similar in appearence to cream, but again with several distinguishing markers.

Champagne is similar to homozygous cream (cremello) in that it dilutes both skin and hair pigment, but differs in that heterozygous cream dilutes only hair and not skin. Champagne horses have pink or pumpkin skin (sometimes mottled) regardless to how many genes they carry.

There is currently no test for the champagne gene.* The best way is to have known a foal from birth - champagne horses have a few unique pointers that ocur from birth.

*A test for champagne is now available - the mutation responsible for champagne has been identified by the University of Kentucky.

One unusual trait most champagne horses have is that they are born dark - bay, black or chestnut - but with pink skin and blue eyes. As the foal coat sheds out, they lighten in colour, the skin mottles, and their eyes darken to an amber or hazel shade. This is the reverse of most horse colours, which tend to be born pale, and darken as they grow older.

Champagne dilutes black and red pigment - black becomes a lighter chocolate colour, and red becomes a golden colour.

Champagne on chestnut gives Gold Champagne. These horses are very similar to palomino in appearance - golden body colour, with pale mane and tail. Some have white mane and tail - others have a more golden shade. They differ from palominos in that they have pink skin (although sometimes this can be so mottled it gives the appearance of being dark in places) and amber eyes.

Champagne on bay is called Amber Champagne. It resembles a buckskin, but the legs, mane and tail will be pale in colour (brownish instead of black).

Champagne on black gives Classic Champagne. This is a striking colour - similar to that seen in Weimaraner dogs. The coat is a sort of grey brown, with darker points, on a pink skin. These horses, like all champagne horses, have light amber or hazel eyes.

[chev]

Thanks Wally!

Finally, silver dapple.

This gene is probably one of the most striking of the dilutes - it works on black pigment, and not only dilutes it but changes it completely to a lighter chocolate colour. Mane and tail are lightened to a silvery cream colour, the effect of which can be quite dramatic.

Silver does not dilute red pigment.

Silver on black horses will cause the body to change to a flat chocolatey colour, with a darker head or mask. The shades range from a pale milky brown colour through to a deep grey brown. Mane and tail hair is subject to a more extreme lighening, and can be almost white. The gene occurs in several breeds - notably the Rocky Mountain horses, Icelandics, Welsh, Missouri Fox Trotters and more.

Silver on a chestnut will have no visible effect. For this reason, some bay silver dapples born to chestnuts carrying the silver gene are mislabelled liver chestnut, or dun, or flaxen chestnut.

Silver on bay creates a colour that varies from a red body with dark legs and an almost white mane and tail through to colours remarkably similar to some liver chestnuts.

Foals are often born with white eyelashes, and hooves show characteristic black and white striping - not at all like the striping seen on Appies and Paints.

This is Causemountain Excalibur, verified silver dapple Welsh pony. If you look closely you can see the white eyelashes on the second pic.

http://img.photobucket.com/albums/v231/bronyfelin-ponies/bob2.jpg

http://img.photobucket.com/albums/v231/bronyfelin-ponies/bob1.jpg

So there we go... the dilute genes. Not all dilutes occur in all breeds - the Icelandic is one of the few breeds that carry all four dilutes, which accounts for the wild range of colours they appear!

[Wally]

Here are all the main duns available in the Fjord horse......any colour you like so long as it's dun!:D :D

[chev]

Brilliant! Shows the lightening along the edges of the mane nicely too - this isn't restricted to the Fjord, although it's most notable in Fjords - it's a characteristic of the dun gene.

[Mossy]

Advice please. Moss started off grey with darker points and zebra legs. He is definitely silver all over now, slight flea bite effect in summer, black skin, and hooves and no dorsal stripe. Both parents were exactly the same. Pure Highland. If I have understood you correctly, dun working on black???. If you have H&H 30th Dec his back end is in the Spooners Picture.

[chev]

Don't have H&H to hand - but is he a bit like the middle Fjord in Wally's post? Sounds very much like dun on black - at it's lightest, the colour is known as silver dun (or silver grullo if it's a Mustang!).

[Wally]

The middle Fjord is known as White dun and is the rarest of the dun colours. The silver dun is bottom right.

Here's Kvikur (bloke) he's silver dun.

[Wally]

What colur would you describe this as?

[chev]

Thanks for the dun stuff Wally. Fjords I know have their own very strict definitions.

As for the colour of the last one... silver dapple on black - and a really nice example of it too! The silver has diluted the black body to that dark chocolate colour, and the mane and tail to that almost white colour. It's really very striking when it's that dramatic!

edit to add that this kind of colouring can actually be quite deceptive - a flaxen chestnut with the dun gene can appear very similar to silver dapple - as can some palominos, amazingly enough, particularly if there are other modifiers like sooty at work.

One way to tell if a silver dapple really is a black with silver is to test for the base colour - if it comes back as red, it's not a silver.

[Wally]

Oohh you do know your stuff....and this chev?

This is facinating........

[chev]

Looks like another silver dapple to me - although the body is lighter than the first, and the mane isn't quite as white, it's still very typical of the way silver modifies a black coat. This one actually has dapples too - in spite of the fact that it's known as silver dapple, not all horses with this gene are dappled at all!

This one does also have a darker mask so it's possible there's a dun gene in there somewhere too, although that's not neccessarily the case.

[Jaimee]

Chev you said dun usually has a dorsal stripe. It is the most consistent characteristic of dun! A horse which has the dun gene will always have a dorsal stripe and it will have vivid edges, countershading can have a similar effect but not usually sharp edges to the stripe :)

[chev]

True - but there are also dun factor markings, which may or may not include the dorsal stripe. A horse that shows dun factor markings may have the dilute body colour, the mask, and the lighter hair in mane and tail for example but no obvious stripe - it's believed that dun factor markings may be part of a more complex set of genetics than a simple dun gene (especially given the fact that horses left to breed untouched can develop dun colouring over several generations where none of them carried the dun gene to begin with).

To register a horse with a dun horse society though it must have a dorsal stripe.

[Floob]

Wally - we have those exact pictures hanging up on the wall at the RS.

So Freyja is a red dun (Fjord brown dun on Chestnut)

And melody is a bay dun? she almost looks like a bright bay, but with distinct dorsal stripe and dark (but not quite black mane and tail).

Honey is also a bay dun, but much lighter and more like buckskin

Joe must be buckskin then? He definetly has black points and a black mane and tail with yellow body, but he goes darker in summer and he gets dapples?

[willumau]

Hi Chev
Thanks for all your information on dilute genetics. In October I posted photos of Velvet who was born very very black. Her Dad is Perlino so we knew she was a dilute and you advised she was Smokey Black. Her colouring has really changed now and I have posted some photos of her at 11 weeks.
Link below

http://www.newrider.com/forum/showthread.php?t=99889

The stallion owner has advised that she is a Black Buckskin because she also has Agouti. What I am surprised by is the light buckskin colour patch that is growing at a rapid pace from her nearside shoulder, it just suddenly appeared as a small patch at the top of her leg when she was about 4 weeks old and is spreading fast - it is now all up her shoulder (as in photo). If you have time, I would really appreciate your comments in my post. I have also noticed some horizontal striping going around her neck, it is black/darkred shaded striping, difficult to see unless you are close up.

Considering I was expecting a Palomino foal from my Chestnut mare I am intrigued by this little foal of many colours.

Lynda

[Nik-n-Kia]

I know a stallion that is double dilute for cremello and palomino and If he is out to another palomino then he usually produces either cremello foals or light palominos. When he was put to a strawberry roan he produced a Palomino the first time and a buckskin the second and whe he was put to a black mare a gorgeous gold/black dun faol was the result.

i always wondered what the breeder meant by double dilute but I didn't want to seem ignorant by asking!!!

Here is the buckskin.... Iwas gonna buy her but parents said no :mad:

Nikki xxxx

[chev]

willumau - that's an amazing change! Yes, she's buckskin not smoky black. It's unusual to find bay based foals born quite that dark, but it can happen; one of my fillies was born black and shed out to the most incredibly dark bay. More unusual still to see a buckskin foal born that dark! but she'd definitely buckskin! :D

[willumau]

Thanks Chev
The stallion owner commented that Velvet is the darkest black on a foal that she has ever seen on her stallion's progeny. She too was surprised how dark she was. She also confirmed that her Perlino is also double Agouti. He has produced Palominos as well. She 100% guarantees palomino or buckskin foals from non grey mares - I thought that was very brave ;)

I must admit searching for photos of Black Buckskins from foal to adult has proved unfruitful for me. So I will post photos of Velvet at different stages in case someone has a similar colour breeding experience.

Lynda

[Nik-n-Kia]

Hi chev

i posted before about double dilute in my previous post but could you explain it to me???

If you read my post (with the Pic)

Nikki xxxx

[chev]

Sorry Nikki, missed your question :o

First off, a double dilute is just a horse with two cream genes. Put at it's simplest;

Perlino = bay with two cream genes. Homozygous perlino can mean a couple of different things... it could be that they mean homozygous for cream - in that case, it's pretty obvious! It could mean he's also homozygous for agouti (bay) *and* cream - which is what it should mean. That would mean that he'd only ever throw buckskin or palomino foals to solid mares (bay, black, chestnut) as the stallion willuma mentioned does. It is guaranteed in a case like that - he will always pass on both cream and bay, so foals to solid mares can only ever be palomino or buckskin.

Homozygous cremello is kind of self-explanatory. The stallion would have two copies of e (chestnut) and two copies of Cr (cream). On chestnuts, the only possible outcome is palomino. On bays, you could get buckskin, palomino, or smoky black, depending on the exact genetics of the bay.

There's no such thing as homozygous palomino. Homozygous means a horse carries two copies of a certain gene (cream, in this case). Homozygous cream = cremello, perlino or smoky cream. A palomino is a chestnut horse with *one* copy of cream - heterozygous for cream.

I think the stallion's owners are trying to make clear that any foal born would have at least one copy of cream (possibly two, if the dam carries a copy of cream too).

I'm guessing that when you say strawberry roan you mean chestnut with roan? If so, the cremello stallion is actually perlino or smoky cream - chestnut roan is chestnut base with a roan gene. In order to produce a bucksin foal (bay with cream) the sire has to pass on black; so we know that the stallion has a black gene. That makes him either black with two cream (smoky black) or bay with two cream (perlino). It's impossible to say without testing him, since chestnut based horses can carry bay and will still be chestnut - but the one thing we do know is that the stallion is not cremello. :)

He is homozygous for cream, certainly; not cremello, not 'homozygous for palomino', and possibly, if the last foal you mentioned is smoky black and not buckskin, not even homozygous for bay. :)

[Nik-n-Kia]

Thanks chev i was just unsure as to what she meant.

She breed lovely horses and one day I would like to own one of her horses (like the one in the piccy) do you think that a clydesdale X arab would have anything anatomically wrong with it???

The 2 offspring I have seen have great movement and conf is good but someone told me that it was a blasphemy to X arabs and draughts is this true???

I'm just curious I guess as I have my heart set on one of these horses for the future. Arab X with lighter horses don't suit me as I am quite stocky myself and I prefer to have weight under me :rolleyes:

This is the stallion

Thanks

Nikki xxxx

[ambatt]

People have been crossing Arabs with Percherons for a long while and they are rather nice (but Percherons have Arab in their genetic makeup anyway).

Crossing with a Clydie could be a bit hit and miss, like crossing Shires and TBs here to produce heavyweight hunters, get the mix right and you get a useful and nice looking horse, get it wrong....

and there is no way to tell!

[chev]

Nikki, is the pic you posted the stallion that's homozygous for cream? If so, I'm afraid his owner has got it wrong; he's a palomino; chestnut with one cream gene. He's heterzygous for cream, so there would always be a 50% chance of a dilute foal when he was used on solid mares. The reason he's produced cremello on a palomino mare is because both parents have passed cream on.

The main difference in breeding terms is that using a cremello stallion guarantees a dilute foal; using a palomino doesn't.

Echo ambatt with the cross - Arabs and Clydesdales are very different in type and height; you could end up with a lovely foal, or you could end up with something that has the height, head and feather of a Clydesdale on little Arab legs... Bit of a gamble that one!

[funkyfilly_sos]

Chev, you really know your stuff!
I wish I had half the knowledge on genetics as you had............ *dreams*

[Nik-n-Kia]

Thanks Chev

I suppose it's like most crossing it's a hit or miss!!

Thanks for clearing all that up for me!!!

Nikki xxx

[old_woman]

Chev, your post on duns was fascinating (I have always loved duns - but oddly never had one ...) especially about it being an atavistic colour.

Tell me, please, about the colour of the Exmoor ... sometimes I have read it described as "wild bay"; sometimes I have read that they occur as "bay, brown or dun".

They seem to me to be remarkably similar to many Przewalski's horses in "markings" (for want of a better term - ie mealy muzzle, belly, groin and axillae) although lighter in "shade" (which is understandable given the environment).

Here is Przewalski's : http://i120.photobucket.com/albums/o171/sheenas_pix/Przewalski.jpg
and here is Exmoor : http://i120.photobucket.com/albums/o171/sheenas_pix/Exmoor.jpg

[floppy]

fascinating!

How can you work out though what the colouring of a foal could be!? if you know the colourings of the foals parents, grandparents and great grandparents?

Everyone has tipped so far that my foal ist going to be chesnut with a star.:eek: :D

(its driving me absolutely potty waiting for my foal to appear.)

[chev]

Edited to add the pearl dilution to thread...

Pearl has been documented in Iberian/Spanish horses, and Quarter Horses. It is a reccessive gene, meaning a horse must carry two copies in order for the gene to be expressed. One copy does not alter the appearance of the coat colour and two copies means it will be fully expressed.

It does, however, react to the presence of the cream gene; if cream is present, the pearl dilution gives the appearance of a double dilute.

On a chestnut base, the coat colour is diluted to a pale apricot colour, including mane and tail, and the skin appears pale. In combination with cream, it produces pseudo double dilute colouring, including blue or green eyes.

More information and genetic testing can be found here (http://www.vgl.ucdavis.edu/service/horse/coatcolor.html#pearldilution), and this site (http://www.newdilutions.com/pearl/index.htm) explains more.

[pineapple]

i have seen an andalusian stallion described as champange. i was wonder what colour combos could result from breeding with a palomino and bredding with a chestnut. the chestnut father was bay and the mother was chestnut. i dont know i that makes any differnce.

thanks:)

[Spoof]

I've heard some news on Champagne testing - UC Davis announced they have a marker test, along with dun coming soon. I believe it is in the final publishing process. :)

[chev]

The dun zygosity test is available now, for select breeds. The gene itself has yet to be identified but certain markers associated with dun are now known in some breeds.

The dun test is not yet available for PRE, Andalusians, Lusitanos, Paso Fino and Peruvian Paso horses, in whom the markers have yet to be identified.

I didn't know that champagne was about to become available, but a test for pearl dilution is available now too.

[Jen_e_Jen]

What colur would you describe this as?
I work with Rocky and Kentucky Mountain Horses, and we would call that Dark Chocolate. This is kind of the "Hallmark" color of the breed, although they come in all colors and mine is bay.(oddly rare in this breed).

[Zingy]

Looking at duns, how do 2 grey parents produce 2 yellow dun offspring and 1 grey dun? The grey dun has a grey/ black face and grey/ brown body which will presumably go grey eventually. The yellows appear to have no grey in their faces.

Are both parents originally yellow dun gone grey or one a grey dun and one a yellow dun? Though one, if not both, has a white mane & tail - would this be the case with a dun gone grey?

[chev]

It's basically the same as two greys producing bay offspring; both parents obviously have only one copy of grey, and in the case of the yellow duns neither has passed the grey on. In the third, one or both has passed on grey, resulting in a foal that goes grey. :)

[Zingy]

So is a grey dun effectively a yellow dun going grey? I'm confused then as I thought a grey dun had a different base colour :confused: I thought from your initial post on duns that the yellows would be dun on bay and the grey dun would be dun on black with a grey gene?

Which would make parents some kind of dun but both gone completely grey, including in 1 case having grey mane & tail and no dark points any longer :confused:

The only thing I remember about genetics was on tall & small peas. I don't think it ever went much beyond that, and I guess this is a little more complicated:D

[chev]

Problem is the terminology really. Strictly speaking a black + dun would be called black dun, mouse dun, grullo or grulla; but because the dun dilutes the body to a greyish shade, people call them grey dun. It's a bit like the fabled cream dun; that gets used to describe various duns most of whom have no cream in there at all.

Dun + grey would be grey dun... but once the grey has really got to work on them the dun becomes invisible and they're called grey.

We're only just startign to understand the various colour genes really and terminology varies from one place to another, so there's lots of inconsistency when it comes to naming colour (especially when dun gets involved!).

[Zingy]

That makes sense. He's been described to me as a grey dun and definitely to go grey and also a silver dun that definitely won't grey out :rolleyes: No evidence of him going grey yet, but from white hairs on his face I assume he will.

I was just surprised to find 2 yellow dun full sisters and couldn't figure out how the various colours came about, as I assume this certainly isn't based on yellow :)

http://i189.photobucket.com/albums/z261/rathcreaprincess/Conf5.jpg
http://i189.photobucket.com/albums/z261/rathcreaprincess/1-1.jpg

[chev]

He definitely looks like he's greying out. If he was black + dun with no grey, his head would be darker - you can see grey starting to work on his cheeks and around his eyes. The darker marking on his nasal bones is typical of grey. His mane and tail are also definitely showing signs of grey - they would be the same kind of shade as his legs and nasal bones if there was no grey.

He's lovely... very pretty colour!

[Spoof]

Current news on the Champagne testing;

Hello all,
I'm Debbie, the one who found the champagne gene. I have the results
on almost all of the horses that people sent to Val for me or that
people sent directly to me. The scientific manuscript is in the review
process and I'm working diligently to wrap up any changes requested by
the reviewers as well as complete the molecular testing so everyone
can have their horses results. The tests don't always work the first
time on every horse and I have a few that the DNA I extracted the
first time didn't seem to work. I am working on new extractions and
tests even as I type this. I found some errors in my genotype record
file as well and I am working to verify each and every test I have run
by going back over the data. The research manuscript will probably be
published fairly quickly after it is through review and resubmitted.
I want to give a huge THANK YOU! to everyone who sent in hair
samples making it possible for this project to be so productive so
quickly. I will be sure to have the result letters mailed out to you
all as soon as the manuscript is accepted for publication. I have the
envelopes addressed and ready to stuff and mail already thanks to Val
and her help.
Debbie

[LeftBrainer]

My boy seems definitely to be dun then:D I've had people assure me he's a chestnut:rolleyes: which with his winter coat he's quite ginger but.... He has dorsal stripe, zebra stripes, cobweb under his forelock, brindling over his shoulders and a little touch of black in his tail. In summer he's tawny lion coloured:) Sounds like a dun to me:cool:

[chev]

Some red duns are so lightly diluted they can pass as chestnuts (albeit a pale one).

Yours definitely sounds dun - any piccies? :D