The Horse Forum banner
Status
Not open for further replies.
1 - 20 of 56 Posts

· Registered
Joined
·
71 Posts
Discussion Starter · #1 ·
Is anybody out there interested in Equine Color Genetics? I'm interested in seeing your unusually colored horses. I'm hoping we can put together a kind of knowledge base of rare colors, and observations about colors to help out with the discovery of new color genes. I'd like to see colors like Black Chestnut and Black Palomino (chestnuts who shed out to black in Spring, and palominos who shed out to black at first shed - often chocolating up at age 3 or so); silver dapple; champagne; pearl - or something you have in your back yard that nobody knows what it is - please let's see 'em and talk about them here!

Also any information about REMNANTS of genes in subsequent generations (eg. a non-roan horse with roan ticking from two generations ago; a non-Champagne horse, with frosted mane, from a champagne predecessor; etc). If it seems unusual, or out of line with known breeding inheritance, let's talk about that!
 

· Registered
Joined
·
803 Posts
I am extremely interested in color genetics! I have done a good bit of reading on it and although I am still pretty fuzzy on Appy and Paint patterns I have a relatively firm grasp on solid colors and the possibilities from different combinations. I know of a site that has a lot of very good material, if anyone is interested PM me.
 

· Registered
Joined
·
2,472 Posts

· Registered
Joined
·
71 Posts
Discussion Starter · #4 ·
Great website. Nicely laid out, and pretty horses too.
I love the little shetland mare, and would be interested in buying her if I weren't living in the UK. Already done my share of importing this year!!
 

· Registered
Joined
·
837 Posts
I love knowing about color genetics... also have a number of unique individuals

My Amber Cream Champange Tobiano mare. She's a 6yr old American Saddlebred


My Bay or Black (not sure - haven't done the DNA test yet) Max. Sabino mare. She's a 6yr old Clydesdale


I will get to bring home my cremello American Saddlebred colt this fall... he's just a "run of the mill" cremello though.

I also have a pretty "run of the mill" Palomino American Saddlebred colt, 4yrs old. He goes from pale "peach" colored in the winter to a deep dappled gold coat in the spring/summer. I have to get updated shots this year still - he's got a lot more "soot" on him... this photo was Apr 15 of this year, and was his second ride under saddle
 

· Registered
Joined
·
88 Posts
ooo boy...

I have "Fathom" who's a yearling maximum white and black tovero filly who we're sure is positive for sabino and splash and most likely frame as well. She's 98% white and 2% black with one blue eye and a TON of ermine marks and cat tracks hidden across her (sometimes they only show up when she's wet). We're also 99% sure she's homozygous as she comes from heavily homozygous stock (parents are both tobiano, sire's tovero by homozygous sire and solid dam and dam is tobiano out of an unknown status tobiano sire and a solid dam) and she's also a true medicine hat!






and

"Sedona"

who's a sorrel splash/sabino overo mare out of a splash/sabino crop out AQHA sire and an overo dam (presumably splash/sabino/frame as I've never seen a photo of her) we're almost positive she's homozygous for sabino and most likely splash since her dam's side has a TON of Splash. She's also starting to roan out EVERYWHERE. IE: white hairs scattered all over her body. However I think this may just be sabino ticking as there's no real roan in her pedigree anywhere close up front. We also are pretty sure she carries the frame gene as well, if she doesn't she's the weirdest marked splash/sabino I've EVER seen. The two photos of her left side are of her from March when I first got her so pardon her lack of muscle/condition and the rest are from June... And I think she may be in foal:




 

· Registered
Joined
·
71 Posts
Discussion Starter · #9 ·
Riding well

... this photo was Apr 15 of this year said:
http://i113.photobucket.com/albums/n225/riosbravo/Finlay/Ap15/P4152850sm.jpg[/IMG]
Hey that palomino is traveling in a very nice outline for a second ride!
 

· Registered
Joined
·
837 Posts
Thank you... he's a great horse, and very willing to try for people, and extremely intelligent. We haven't put a lot of work on him because he keeps growing on us, and with his intelligence it'd be really easy to push him too fast.
 

· Registered
Joined
·
71 Posts
Discussion Starter · #11 ·
Thank you... he's a great horse, and very willing to try for people, and extremely intelligent. We haven't put a lot of work on him because he keeps growing on us, and with his intelligence it'd be really easy to push him too fast.
That sounds very wise. When I was barrel racing, my trainer wouldn't allow me to let anybody else ride my horse. He used to say the work we put in him was carefully thought out, and took many repetitions for him to 'get' ... and what it took us hours to put in, someone else could take out in just a few minutes! Must be even more true of a young horse, I guess.
 

· Registered
Joined
·
3,077 Posts
yeah i love equine genetics! my fave rare colour is probable sable cream dun which is black + agouti + champagne + cream + dun!
so basically amber champagne with cream and dun genes too!
 

· Registered
Joined
·
71 Posts
Discussion Starter · #13 ·
yeah i love equine genetics! my fave rare colour is probable sable cream dun which is black + agouti + champagne + cream + dun!
so basically amber champagne with cream and dun genes too!
Sounds very pretty. I'm not a big fan of the Agouti gene, myself. But I think there are forms of black that are not subject to it, as in Friesians, and Welsh Cobs - they definitely have some kind of dominant black thing going on there. I wish they'd get on and 'discover' it - so I can figure out where it comes from, and how to control it!
 

· Registered
Joined
·
3,077 Posts
not a fan?! so you don't like bays? :p

anyway here is a pic of a sable cream dun



and a black silver dun


yes you a right, a true black horse is dominant black, not to do with agouti gene. dominant black causes black pigment (red and black) and the agouti gene only controls/ limits it. Which is why get variations of bay.
 

· Registered
Joined
·
71 Posts
Discussion Starter · #15 ·
Pretty colors!

Thank you... he's a great horse, and very willing to try for people, and extremely intelligent. We haven't put a lot of work on him because he keeps growing on us, and with his intelligence it'd be really easy to push him too fast.
not a fan?! so you don't like bays? :p

anyway here is a pic of a sable cream dun



and a black silver dun


yes you a right, a true black horse is dominant black, not to do with agouti gene. dominant black causes black pigment (red and black) and the agouti gene only controls/ limits it. Which is why get variations of bay.
OOOH - now that's what I'm talkin' bout! What byootiful babies! I shouldn't say I don't like bays - because I like buckskins, etc - the whole points thing - it's just that I don't like that Agouti (A) is dominant over black (EE) and can turn a homozygous black horse into a bay. The only way to breed blacks, is to eliminate Agouti altogether. Or to find a dominant black that comes from a locus OTHER than E. Like, maybe a variant of B/b or K (as in dogs). Am I losing you here?
 

· Registered
Joined
·
71 Posts
Discussion Starter · #17 ·
B and K doesn't exist in horses. Just E for black. Very easy to avoid bays if you know the genetics of the particular horses, which is only $25 to see if they have agouti or not (in chestnuts for example, since it would be obvious on a bay horse haha, but will tell you if the bay is homozygous agouti or not)
B and K have not been DISCOVERED in horses. One can not assume that everything that has not been discovered in the world therefore does not exist. We are at the very early stages of mapping horse DNA and, with respect, there is much more that we DON'T know ... than there is that we do know. For instance, how does a chestnut horse ee (no black gene whatsoever) get a black mane and tail? Not possible - but it happens all the time, and we don't know why.

It has been considered, by some researchers, that all horses are actually homozygous for B - which is the indicator for black skin - which is why it is not listed among the known locii.

This is my ee chestnut mare. She has no black gene at the E locus. There is definitely dominant black somewhere in horses, and it sure looks like it ain't at the E locus.
 

Attachments

· Registered
Joined
·
71 Posts
Discussion Starter · #18 · (Edited)
Agouti Test

Also, testing a horse for Agouti does not tell you whether it is A+, A, or At. It's not always obvious, because a horse with A/At will appear as a bay horse, but you don't know he can produce brown (or nearly black). There is also debate as to whether brown is actually entirely caused at the A locus, or whether there are other factors in play. Since Pet DNA services keeps the test procedure secret - nobody knows how they test for brown, except them. There are a lot of black horses in brown lines. If you study pedigrees, this becomes apparent very quickly. Look at the Morgan breed, too - where browns, livers and blacks are more prevalent (probably descended from Welsh Cob).

This brown stallion, (At a E e) was registered as a bay. But his 'a' gene came from a liver chestnut horse - so he only gave liver and brown. 90% of his foals were darker than his red mares 10% were the same red shade as his mares, and zero foals were lighter than his mares. There's so much we don't know about how Agouti series may affect the shade of red - and what effect the presence of other unknown modifiers might have.
 

Attachments

· Registered
Joined
·
4,510 Posts
^

The dark on chestnuts with no black can be explained by sooty or counter shading. My chestnut mare has a black tail and a very soft faint wide dorsel stripe. It's classic characteristic of counter shading, and your mare is a classic example of sooty.

A buckskin with sooty:



There are classic and almost infamous examples of sooty completely altering the color of a horse so as to swear it was bay or black without genetic testing.
 

· Registered
Joined
·
71 Posts
Discussion Starter · #20 ·
Sooty gene theory

^

The dark on chestnuts with no black can be explained by sooty or counter shading. My chestnut mare has a black tail and a very soft faint wide dorsel stripe. It's classic characteristic of counter shading, and your mare is a classic example of sooty.

A buckskin with sooty:



There are classic and almost infamous examples of sooty completely altering the color of a horse so as to swear it was bay or black without genetic testing.
Yes, I know a lot of people accept that. But not all sooty horses shed out to absolute black every Spring. My black palomino mare, for example, had to be tested twice to come up with any chestnut result at all - and even then, it was a very weak result. Would that be caused by sooty? Sooty is just a theory like everything else. There is no test for sooty, and it can't be proven or disproven. At the moment Sooty is just a label we give in an effort to lump things that seem alike to us into a category. When we get more educated, we begin to break those labels down into new categories, and subcategories, according to how the individuals in that group differ from the other individuals in that group. Then it takes generations to discover whether we can reliably reproduce those characteristics, and we observe the pattern of emergence to discover inheritance traits. It is only THEN that the geneticists sit down and try to pinpoint what breeders have already discovered. We must not get set in the idea that what we think we know today is all that will ever be known about anything. We are in the infant stages of horse color genetics and we know much less than what we DON'T know. That's why it's important to gather as many observations as possible, and keep an open mind. When I refer to black chestnut, or black palomino I mean that these horses have specific pattern of characteristics that are similar to each other ... and distinctly different to to other horses that can appear to be like them. Some horses have dapply sooty. Some have evenly spread over the back and neck - is it the same? Some is caused by seasonal changes - is that the same? Some palominos shed to absolute black at first shed, some chestnuts shed to black or purple every spring, is that the same? And at least in Lace's case - genetic testing does not give a clear, strong, satisfactory, result. Also sooty does not, traditionally, cover the soft points or the muzzle. Thanks for the picture of your beautiful mare - I agree with you that her coloring DOES appear to be caused by evenly and distributed sooty. My stallion has similar shading, but it's not at all the same as Ruby's coat. Sooty does not fade in the sun. Ruby bleaches out to burgundy. By the way, what breed is your mare? She's very pretty. Her muzzle is very pale, and could indicate the presence of At (brown). Looks like a seal brown, actually! I'm glad you sent this - because I'm surprised her genetic results came back as chestnut! Very interesting, Thanks!! Notice there doesn't actually appear to be any red in her coat - is this always the case, or does she turn reddish at certain times of the year? Very cool!
 
1 - 20 of 56 Posts
Status
Not open for further replies.
Top