Because I'm considering my filly as a possible breeding prospect [once she's proven herself undersaddle] and the frame gene does exist in Thoroughbreds, I thought I would ask the question.
She is definitely sabino, there is no question of that. Lots of leg white, which is all jaggedy at the top [and two of her socks/stockings come to arrowhead points], and symmetrical face white.
BUT... might there be a possibility of frame?
She has a LOT of ermine marks, indicating that something is trying to suppress the white on her legs. I haven't counted them but she has a whole bunch, and not just on her coronets. She has a couple of chestnut spots mid-cannon sort of region.
The other thing is, her face white is top-heavy and totally avoids the lower half of her face.
The horse I am most likely to breed her to is an Arabian [he puts divine fronts on all his babies, which is why he is top choice - because that's what I want to improve on with Magic] and thus far the wisdom is that the frame gene does not exist in the Arabian breed [nor do I see any traits in the stud I want to breed her to] but I would still like to know whether it would be worth testing Magic, or if I'm just seeing things.
The pictures don't really show the ermine marks that clearly but the face white is I think probably the most telling bit of white on her body. Experts... what say you?
Ok so with no frame in the intended stallion there's absolutely no chance of a lethal white foal, but I think I will test her to be safe... eventually. Just in case something else crops up as a possible sire for her future baby that does have a chance of having frame, like a QH or Paint [I like the stock type/TB cross, got a friend who has one that can jump the moon].
Regarding Agouti, the stallion I intend for her is chestnut, so the only colour possibility for the foal is chestnut [being that Magic, being chestnut, has to be ee, and the stallion also has to be ee], with varying amounts of bling depending on what white genes it does or does not inherit from its parents. But if I'm testing her for frame, I might as well test her for Agouti, to see if there is any possibility I might get a black foal out of her if I bred her to a different stallion. I like black ponies. I also like chestnuts, and bays, so regardless I'd be happy.
So the ermine marks are likely to be some other white suppression gene in play? Sabino and splash are both definitely present in the Thoroughbred breed yet we don't see many loudly marked TB's, so there has to be some gene or another that suppresses the white on them... right? [to clarify, I class frame as both white suppressive, and white causing, because it wants to keep the legs coloured]
This breeding idea I'm flinging around won't be happening for a few years yet, I really don't need a green horse to train up AND a foal to handle! Plus Her Highness has to prove herself worthy first... only reason I'm even considering it is because other than her neck and the angle of her humerus I quite like how she's built. Her feet are tiny at the moment but hey, she's a baby, there's time yet for them to get bigger.
Lol, I'm curious about my brown sabino gelding. Would he test positive for Sb1? Is he homozygous or hetero for black and agouti [I have no idea what colour his parents were]? Am I really right calling him brown? [he is "bay" all over except that his muzzle goes a little mealy in winter - I am pretty sure he's brown but kind of want to know for sure]
At least with Little Miss Red there's ONE thing I know for sure - that she's homozygous for red factor. And I have at least a 50% chance of her throwing sabino. Bred to a chestnut sabino stallion [namely, the stud I am most seriously considering - you might know of him? Kalody Park Beraq?], she's going to throw chestnut, and has a good chance of throwing something with a lot of white.
Lol, the horse I'm specifically thinking of testing is an Anglo Arab, so if Sb1 exists in either breed [or both] he might have it. Magic is full TB, and I don't know that I'll bother with testing for Sabino for her. Frame fo sho, Agouti fo sho, but chances are she's hetero for Sabino, based on what I know about her bloodlines. Her sire's bloodline likes to throw bays with a little bit of white, or chestnuts with a LOT of white. Her dam's bloodline, I don't know enough about, but I've heard of a lot of horses from her damsire that are brown with no white, so statistics are in favour of Magic being heterozygous.