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Re: Re: Re: Re: Re: Re: Sulphur's Khanketsuba |
| Name: |
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Diane Pinney |
| Date Posted: |
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Apr 11, 08 - 2:26 PM |
| Email: |
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spanishsageranch@earthlink.net |
| Message: |
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Sorry all been busy. Erin, I think your friend was mistaken. I will do my best to explain color genetics, and then refer you all to a good and simple web site, in the event I am unable to explain clearly.
Horse colors are black or red.
Black horses have genetic of at least one dominant E gene; when you do a color test, it is either EE or Ee. This is what determines the base color. I believe E stands for Eumelanin, which is what produces the black pigment.
A red horse with have no dominant E gene, but only two recessives, being ee. Therefore, the horse is not able to produce black hairs, only red hairs, therefore you have a red horse. You cannot have a black horse from a red horse, but you can produce a red horse from two black horses if both are Ee, and you can get "ee".
What makes a bay horse is the Agouti gene, which affects where on the horse the black is expressed. It only effects the Eumelanin. It is called A. So, a bay horse would have to have at least one dominant A gene to be bay, they would be tested as AA or Aa. A horse with aa would not be bay, but completely black.
Since the Agouti only effects the black pigment, if a red horse carries a dominant A, you cannot tell by just looking at it, because the horse is incapable of producing black pigment, so you couldn't see where this gene is restricting it. HOWEVER, that does not mean that the horse cannot carry the dominant A, just you can't see it. So, a red horse that carries the dominant A, bred to a black horse, CAN produce a bay. It could pass on the A gene, and the black parent would pass on the a (recessive).
Dun is considered to be dominant. So, added to this that a horse that his heterozygous dun, in other words has a dun gene and a non-dun gene, has a 50-50 chance of producing a dun.
So, back to the grulla bred to grulla.
Grullas, being defined as a black horse with the dun gene, would be either EE or Ee. They both would be "aa" ; if they were not, one would be a bay horse, not a black.
So, the only colors you could get would be EE, Ee, or ee. You would only get ee (a red aka chestnut or sorrel) horse 25% of the time if both black parents were Ee. Mostly you would get a black based horse.
Adding the dun to that, if both parents were Dd (being heterozygous dun) you would similarly have a 25% chance of producing a non-dun, so basically 75% change of a black nondun, 25% chance of a red non-dun, but your chances of producing a non-dun are only 25% overall.
Therefore, with breeding Khan to Alma, the possibilities are black dun, red dun, black horse or red horse.
If this is too confusing, try going to
http://www.dungenes.org/genetics.htm
I do have one or two recent pics of Khan, Kim I will email them to you, and am planning to update my web site asap. I did some reading about FrontPage2003 and think I understand it better now. I understand genetics FAR MORE than I understand web page design for now!
Diane |
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