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Tobiano + Roan....

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rabbitsfizz
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Tobiano + Roan....

Is this true?

 

The foal will either be Tobiano or Roan. They are mutations of the same (KIT) gene and a horse can only carry two copies of each gene. In this case the roan mutation and the tobiano mutation. And only one copy of each gene is passed from each parent. A roan tobiano horse will always produce foals that are either roan or tobiano but never both when bred to a non-roan, non-tobiano mate.

 

I am thinking it probably is but am having a bit of trouble getting my head around it!!!

Daylene Alford
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Well, yes and no.  Tobiano is

Well, yes and no.  Tobiano is not technically on KIT is is very very close to KIT so in except for very rare cases should be linked to KIT.  

So yes, unless something weird happens (which occasionally happens in the world of genetics).  All foals of a horse who carries both Tobiano and Roan will be either Tobiano OR Roan.  

Now that being said here goes the "weird" stuff.  In dogs it has been discovered that two brown mutations can be on the same allele.  So this would in effect be the same as having a horse with Tobiano and Roan inherited together.  If it has happened in dogs it could happen in horses.  Would both mutations be allowed to express in such a situation?  We "think" they would but can't be positive.   

If you'd like to get more in depth I wrote this a while back.  http://colorgenetics.info/equine/kit-gen...

rabbitsfizz
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Thanks Daylene- AND I

Thanks Daylene- AND I understand it!!

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