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The Sabino gene in Arabians?

8.6K views 10 replies 9 participants last post by  CheyAut  
#1 ·
Someone is trying to sell me on an unstarted 4 year old that carries the sabino gene. She kept mentioning how high the chance of her throwing sabino babies are. Ever the skeptic, I figured I'd ask here: How does that gene work? And does anyone have an Arab displaying it??
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#2 ·
Any Arabian with white markings has the sabino gene. Doesn't mean the mare will throw maximally expressed sabino markings, just because she has the gene.

If you want a maximally expressed sabino, you need to breed for one. Just carrying the gene means squat.
 
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#3 ·
How does she know she's sabino? Speed Racer is right, but they haven't documented the other sabino genes yet, the ones that are restricted to strictly leg and face white. It's widely believed now that every horse with white markings carries sabino, however it seems to be a different type of sabino that remains restricted to leg white and face white. As minimally expressed sabino 1 can also do this, it is impossible to tell if the horse is a "true" sabino or not unless it tested positive for sabino 1 or has a very blatant coat pattern.

If the mare tested positive for sabino 1, she still only has a 25% chance of producing a sabino foal herself, as if she was homozygous for sabino, she would be expressed in the maximum form (ie. almost pure white). Your odds of a sabino foal could increase by breeding to a heterozygous sabino stud (50%).
 
#5 ·
Erm, if you breed two horses and the stallion is solid, that results in only a 25% chance of the foal inheriting sabino. If the mare is heterozygous for sabino then she is going to be n/Sb as opposed to Sb/Sb (homozygous). The stallion will be n/n for sabino. Out of four possibilities, only one results in sabino, giving you a 25% chance of her passing it on when bred to a non-sabino stud.

If the stud is also n/Sb then you have two out of four genes being sabino and a 50% chance. Load it into the quadrant.
 
#7 ·
>>>>Erm, if you breed two horses and the stallion is solid, that results in only a 25% chance of the foal inheriting sabino. If the mare is heterozygous for sabino then she is going to be n/Sb as opposed to Sb/Sb (homozygous). The stallion will be n/n for sabino. Out of four possibilities, only one results in sabino, giving you a 25% chance of her passing it on when bred to a non-sabino stud.

If the stud is also n/Sb then you have two out of four genes being sabino and a 50% chance. Load it into the quadrant.


You are mistaken. If the mare is SB/n and the stallion is n/n, it **is** 50%, since the mare will pass her Sb 50% of the time, or her n 50% of the time.... and the stud will pass his n all the time.

Here is a rough square-- mare is Sb/n horizontal entry, stud is n/n vertical entry---the four quadrant shows Sb/n, n/n, Sb/n,n/n... so 50/50.


...........Sb.....n
----------------------
...n..|..Sb/n..n/n
...n..|..Sb/n..n/n



If both parents are heterozygous Sabino, the odds of getting sabino rise to 75%-- 50% heterozygous and 25% homozygous--


...........Sb........n
----------------------------
.Sb..|..Sb/Sb..Sb/n
...n..|..Sb/n.....n/n


Sorry about all the ..... I am using them as placeholders, because the posting program ignores the spaces I try to put in, LOL
 
#10 ·
She is just trying to get more money and/or trying to make her sound more appealing. It is not all that uncommon to have very slight expressions of sabino. My mare is by a stallion that had pretty well expressed sabino (four high jagged white legs, lots of face white, and minimal roaning/ticking in coat). Her dam was a homozygous black mare, nothing spectacular white wise. My mare is all black except for two med whites on the back legs, so daddys' chrome was all for naught unfortunately. My mare had my colt and he is expressing a very low amount of sabino(one high white, white ticking throughout coat) even though she really had none and his sire had none. If you check out the link someone supplied above, you will see that even the professional breeders end up with the low chrome from high chrome parents. The likely hood of this mare to produce well marked foals is very low, but you may very well end up with little tiny bits of sabino like that. It is either an uneducated person, or it is just a marketing scheme to make more money, but if she is not a quality animal in your eyes without the potential for chrome, then I would pass her up anyway. Good luck, and keep us posted! Lots of avid arab lovers on this forum. <3
 
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