Post by jamshundred on Mar 22, 2018 15:11:19 GMT
The New Dexter Bulletin Board
3 base colors: Black, Wildtype, Red
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Kirk F
Joined: 25 Apr 2004
Posts: 43
Location: Sandy, Oregon
PostPosted: Mon Nov 20, 2006 8:41 pm Post subject: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
I have been researching cattle color genetics and found it interesting how the various breeds refer to colors differently even though the genetics work exactly the same for all breeds. Most agree there are 3 base colors in cattle controlled by the E (extension) gene locus which controls the extent of the only 2 pigments(black and red) found in all mammals. The 3 genotypes at this locus are ED = Dominant Black (Lots of black pigment overpowering the red), E+ = wild-type (a mix of black and red pigment), and e = recessive red (red pigment only). Notice that Dexter dun is not one of the three basic colors because Dexter dun is simply dominant black (ED) that has been modified by the B (stands for brown) Locus gene (aka tyrp1) which causes the last step in making black pigment to be omitted (resulting in a brown - called dun in Dexters). So Dexter duns are really blacks with a brown modifier. In order to be dun the animal needs to be a black (ED/ED, ED/E+, or ED/e) and needs two recessive brown genes (b/b) at the B locus.
The coloration of the E+ gene in most other breeds is often referred to as wild-type or brown or brown-black or reddish brown-black. Cornahir Outlaw is probably the most famous E+ Dexter. Notice how brown he appears and how black his head, legs, and tail are (his photo is in the AI bulls album). In Dexters, we simply call both E+ and e “red” when they really can be quite different. E+ (Wild-type) is the original color gene for the ancestors of cattle. It causes cattle (especially bulls) to have very dark extremities and can cause an animal (especially bulls) to grow black with age. It also usually causes mealy-mouths (lighter rings around the nose).
Geneticists state that ED (black) is dominant over E+ (wild-type) which is dominant over e (red). This means that a heterozygous E+/e should look like an homozygous E+/E+ but I have found some conflicting information stating that E+ (wild-type) can act somewhat neutral when paired with e (red) allowing the E+/e animal to look more like a true red.
For those of you who have made it this far in this long post, I’m curious if any of you know the color genotypes of Cornahir Outlaw (I would guess E+/E+ B/b carries one dun gene), Saltaire Platinum (I would guess ED/e B/B no dun), or Lucifer of Knotting (I would guess e/e B/b carries 1 dun gene). Also , I would love to hear from those of you that know the genotypes of some of your own animals - Do all of your E+E+ animals have coloration similar to Outlaw? Do they have tan rings around the nose? Do they have dark noses and hooves? Do your E+/e animals (especially bulls) have the wild-type coloration, like Outlaw or are they more similar to true red ?
Also do any of you have any E+/E+ b/b animals? I would think that the b/b (dun) would modify the black pigments found in an E+ animal and would lighten them.
Thanks,
Kirk
PS: Here’s a link describing cattle coloration- Notice that the Beefmaster “brown” bull has the same coloration as Dexter bulls like Cornahir Outlaw. www.sss-mag.com/fernhill/cowcolor.html#base Note the dun referred to in this link is not the same dun that occurs in Dexters.
PPS: I wish we tracked known color genotypes in the online pedigree systems.
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marion
Joined: 05 Mar 2006
Posts: 131
Location: Canada
PostPosted: Mon Nov 20, 2006 9:19 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Wow Kirk! I'm procrastinating night chores, so when I've got them out of the way and can relax, I must read that another 25 times. (You have stated things very clearly, but it will take me some time to get my head around it!)...marion
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Cloverbell
Joined: 13 Sep 2005
Posts: 391
Location: Dickson, Tennessee
PostPosted: Tue Nov 21, 2006 11:00 am Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Kirk, Thank you for this post! Very nice to know there are people like you willing to put time and effort into the science-side of our breed.
I am NO expert but have had conversations with those that are. I seem to recall that there was no dun in Outlaw or Lucifer. I could be wrong though. And I don't know of an E+/E+, b/b but I know of e/e, b/b. Antarres is the later and I have one of his sons (Rafferty) who may be also - (I should get him tested).
I have used an Outlaw son (Striker B) and he is a real ringer for his father in the "wild type" characteristics.
But, your comment that carrying dun would affect the color of a red...It is my understanding that since those are completely different genes it should not affect it. But what do I know?
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Kirk F
Joined: 25 Apr 2004
Posts: 43
Location: Sandy, Oregon
PostPosted: Tue Nov 21, 2006 12:33 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
I based my “guess” that Outlaw and Lucifer both carry dun on my search of the ADCA pedigree database where I found two dun offspring of Outlaw and one dun offspring of Lucifer. In order to have dun progeny an animal must carry dun. I guessed that they both only carry one dun gene each, not two, because they had so few dun offspring.
Concerning dun affecting reds. I agree that it cannot affect true reds (e/e) because dun affects black pigment and true reds can’t make black pigment. However the E+ wild-type animals that we also call “red” can have both red and black pigments, so I propose that having two dun (b/b) genes might cause the black pigments in an E+ animal to turn to brown (but would leave the red pigments alone). So imagine an Outlaw looking animal with his black parts turned brown/dun. That is what I’m guessing an E+/E+ b/b animal would look like.
Kirk
PS. Do you have any known E+/e animals that don't look wild-type and look very true red?
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Cloverbell
Joined: 13 Sep 2005
Posts: 391
Location: Dickson, Tennessee
PostPosted: Tue Nov 21, 2006 1:44 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Without looking at the Lucifer and Outlaw pedigrees myself do you know if those dun offspring were "red/dun" listed, thus possibly/actually red not dun? I know that is how many were listed years ago. Did those dun offspring then produce any that were listed truly as (just) dun?
As far as the E+/e with true red (pink nose) characteristics - Cinnabar is an E+/e, pink nosed bull. He has produced pink nosed and black nosed calves.
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cddexter
Joined: 09 Mar 2004
Posts: 112
Location: Canada
PostPosted: Tue Nov 21, 2006 3:37 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Kirk:
John Potter would be the definitive source, but since I started all this by identifying the second red with my dna work back in '97, I can tell you that Outlaw and Lucifer do not carry dun, so if you have a son or daughter listed as dun with one of those bulls shown as the parent, the breeder has made a mistake, as some other bull is the sire, and the calf is misregistered.
Red completely covers dun, so even if an animal is homo one of the reds and homo brown, the animal will be red and phenotypically indistinguishable from any other red, with or without a dun gene.
John has lots of offspring of both, all tested, and there is no distinction that you can point to with confidence that one red is different from another. You can have light reds with either ee or eE+ or E+E+, you can have dark reds with ee or eE+ or E+E+, and you can have pink noses, black noses, mealy noses (with either), black faces and legs with all combinations of ee, eE+ and E+E+. While you are right about the red/black affect, especially in Holsteins, E+E+ is not always red. It can be brown as in brown swiss and Jersey (who both get black extremities) or it can be pure black in Limos.
I understand (but may not be right for 100% of the cases) that the noses and faces and legs CAN be part of the E+, but are not limited to it. Some of that comes from pattern genes at other loci.
It might be an idea to talk to John, and then come back with the info you get. That way, now that interest is piqued again, you can return with the straight goods. That probably would be helpful to those who haven't read the color stuff published by the ADCA, me, John Potter, and/or discussions on the various sites.
thanks, c.
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Kirk F
Joined: 25 Apr 2004
Posts: 43
Location: Sandy, Oregon
PostPosted: Tue Nov 21, 2006 4:30 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Good idea. I'll talk to John and then report back.
By the way, the 2 reportedly dun offspring of Outlaw are ADCA 11286 and 11287 and are listed as dun (not Red/Dun) and appear to be residing in Canada. The reportedly dun offspring of Lucifer is ADCA 14333 listed as dun (not Red/Dun).
Kirk
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marion
Joined: 05 Mar 2006
Posts: 131
Location: Canada
PostPosted: Tue Nov 21, 2006 8:27 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Hi Kirk, Those two animals are registered Canadian 1716-R, and 2079-R. Both animals are recorded as being red...marion
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JMC68301
Joined: 01 Mar 2004
Posts: 48
Location: Adams Nebraska
PostPosted: Tue Nov 21, 2006 9:25 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
ADCA #14333 is from our herd. She is dun and not red. We are in the process of having her parentage verified.
Jeff Chambers
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Kansas Dexters
Joined: 13 Aug 2005
Posts: 105
Location: Osage County, Kansas
PostPosted: Wed Nov 22, 2006 3:52 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Hi Kirk,
There is a listing of Dexter Bulls on A.I. in the ADCA 2006 Membership Directory on page 12 with the color genotype for each AI bull. However, there are some mistakes (typo's??) for some of the bulls. The one mistake that I know of for sure is Glencara Finerty. His genotype should be shown as: e/e B/B. The ADCA website, AI bull webpage, also confirms that Glencara Finerty is red and does not carry dun.
We have a Glencara Finerty son, O'Bannon's Brogan. Brogan's dam was dun and did not carry red. When you breed a Bull that is red and does not carry dun, to a cow that is dun and does not carry red, you get a black calf that carries both dun and red recessive. That is what Brogan has.
So far, Brogan has sired 2 dun calves: Wakarusa OB Morgan - out of Hillside Mornin Glory, and Wakarusa OB Ginger - out of Oleo Nickel. Both of these cows are black, and carry dun.
Trillium Cluny and Aldebaran Priapus, two of our AI bulls, are black and carry dun. We have a dun heifer that was sired by Trillium Cluny, Wakarusa Nutmeg Cluny - out of River Bend Fancy.
Because the ADCA and PDCA registries require DNA testing to register an animal as red (if both the sire and dam are not already registered as red), we find that some animals have been misregistered as dun because the owners just did not bother to have them tested to prove red. That is unfortunate, but that is what has happened and continues to happen.
Patti
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cddexter
Joined: 09 Mar 2004
Posts: 112
Location: Canada
PostPosted: Wed Nov 22, 2006 4:57 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
lots of good info. In Canada, animals registered as red either are dna tested, are from proven red parents, or are from parents that have proven red behind them, AND cannot be homo brown. Thanks patti--I'd forgotten that PRE-split, the ADCA registrar registered as DUN any animal where the owner wouldn't test, and this has caused a lot of confusion (and made the registry just as inaccurate as it had been earlier, before there was a test for red and the reverse happened: duns were registered as red--and then red/dun and red or dun). Anyone with animals from the vet Harvey Hall will probably have reds registered as dun, because Harvey argued that he knew the difference and didn't need to test, and Rosemary registered every one of them as dun, even though most of us knew they weren't.
Animals that are homo E+ and homo b are red. Kirk raises an interesting question if there were black hairs, would they be dun? So far there aren't any of that combination, but homo e and homo b are pure red. c.
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Cloverbell
Joined: 13 Sep 2005
Posts: 391
Location: Dickson, Tennessee
PostPosted: Wed Nov 22, 2006 5:56 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
Are there really no homo E+, homo dun? That's amazing.
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cddexter
Joined: 09 Mar 2004
Posts: 112
Location: Canada
PostPosted: Thu Nov 23, 2006 2:37 pm Post subject: re: 3 base colors: Black, Wildtype, Red Reply with quote Report Post Mark post as unread
hi cloverbell, not really when you think about it. Most people who are breeding for color want one or the other, so don't deliberately go about mixing the dun and red, because that would defeat the purpose. There may be homo E+,b out there, but none has been found in those tested so far. I think Kirk raised a really interesting point, and John P and I had a good laugh over imagining a sort of red doberman-type, if that's how it works: could start a new trend in Dexter color combinations, as it would be pretty neat looking. If Kirk is right, and I think he may be, I wonder how the assn would go about describing that one. I'll bet John goes to work on trying it out, but it might take a few years. c.
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