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Post by rhonda on Jan 16, 2014 17:34:40 GMT -5
I tested Selby for red..I know he is DUN..the test results are ED/ED--I read somewhere that is black..what? Rhonda
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Post by carragheendexters on Jan 16, 2014 18:17:25 GMT -5
Hi Rhonda,
that means that he carries 2 genes for black, and doesn't carry any genes for red or wild gene. You know that he is dun, so probably didn't test him for dun, but if you did his full colour profile would be EDb/EDb.
What it all means is that he is dun in colour, and does not carry any genes for red colour.
regards Louise
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Post by ssrdex on Jan 16, 2014 22:23:29 GMT -5
I hope you get it Rhonda, it's about as clear as mud to me! I guess that's why I'm on here so much...;-)
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Post by ssrdex on Jan 16, 2014 22:24:04 GMT -5
I hope you get it Rhonda, it's about as clear as mud to me! I guess that's why I'm on here so much...;-)
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Post by carragheendexters on Jan 17, 2014 7:54:03 GMT -5
Hi Joel,
it's not that complicated that it is sometimes made out to be. Selby carries 2 genes for black and 2 genes for dun, and doesn't carry red at all. The simple version is that his genotype for colour is ED(black)b(dun)/ED(black)b(dun).
Still clear as mud? LOL
regards Louise
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Post by kansasdexters on Jan 17, 2014 9:43:26 GMT -5
It's not complicated, if you know the different terminologies used in reporting color genotypes. Part of the confusion comes from different labs using different terminology. There are two gene pairs involved and they occur on different chromosomes.
Whether a Dexter is genetically "red" or genetically "black" is determined by a specific locus (gene pair) on Bovine Chromosome 18. This locus is also referred to as the "Red/Black" locus, or the "Extension" locus, or MC1R (melanocortin-1 receptor gene). A result of ED/ED, is a test result for a homozygous, genetically black Dexter. The "E" stands for "Extension" and the "D" stands for "dominant black".
Whether or not a Dexter has the genetics for "dun" is determined by a specific locus, on a different chromosome, Bovine Chromosome 8. When the dun gene occurs as a homozygous pair, b/b, it modifies the expression of dominant black (ED), so it is expressed in the animal as brown (dun) rather than black.
When the dun gene "b" is paired with the non-dun gene (B), the test result is B/b, and the animal is said to "carry" dun, but it's color is not considered to be dun.
The dun gene, as a homozygous pair, b/b, only affects the expression of dominant black (ED), and it has no effect on the coat color of a red animal. Thus, a red Dexter (E+/E+, or E+/e, or e/e) can be homozygous for dun, b/b, or carry dun, B/b, but it is considered to be red, and it is registered as "red".
All dun Dexters are genetically black, because they must have a least one dominant black gene (ED) at the Extension locus (aka the MC1R locus), in order for the homozygous dun gene pair (b/b) to be expressed.
If a breeder only asks the lab to test at the Extension locus (MC1R), then the test result for a dun animal will be "Black". In order to confirm dun, the lab must test for dun, and this is a separate test.
If a breeder only asks the lab to test for dun, then the result will not indicate whether or not the animal has red.
In order to know the full color genotype of a Dexter, the lab must be instructed to test for the Extension locus (MC1R) and for the dun gene -- two separate tests.
Patti
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Post by rhonda on Jan 17, 2014 15:58:22 GMT -5
So, because I only checked to see if he carries red..they didn't test for dun. Which I didn't need to test for because he is dun. Rhonda
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Post by kansasdexters on Jan 17, 2014 17:29:23 GMT -5
Rhonda,
The lab runs the tests that you order and pay for. If you asked them to check for red, then they run the test on the Extension locus (MC1R) on Chromosome 18. That test will tell you if an animal carries red (ED/E+ or ED/e) or is red (E+/E+ or E+/e or e/e). Since you know that your bull is not black, and the test told you that your bull is not red, then by default, he is dun.
But, if you want to prove that he is dun, then you also ask the lab to run the test for dun; and if he is genetically dun, the dun test result will be b/b. If he carries dun, the dun test result will be B/b.
Patti
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