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Re: [RC] Palominos - KrisAll correct, but small clarification needed. (i'm a huge color genetics nerd, and got several credit hours for an independent research project in the field) There are several things that can cause a chestnut to be flaxen. One way is the recessive flaxen, at an unknown locus. The horse has to genetically be homozygous recessive at the extension locus (resulting in chestnut) in order for the homozygous recessive flaxen to be expressed. Therefore, a bay son of Fire N Ice (who is eeff, son would be Ee?f) could still throw a flaxen foal. This flaxen is very striking. There is one other way to cause a flaxen chestnut that's completely unrelated to this, and is starting to become more common in the Arab. With less selection pressure against white markings, the dominant Sabino pattern gene (a pinto gene which appears to be recessive but is not) has started to appear. I have a wildly nerdy theory as to why this occurred, but I won't bore you with it. You can see it in the Khemosabi line a lot, but I'm riding a loud Sabino right now that has no relation to that line. But when a horse is a chestnut and also receives one copy of the Sabino, it often can become somewhat to very flaxen. and if body spots aren't evident (which they usually aren't in this breed) then it may be confused with a recessive flaxen chestnut, which makes for a lot of confusion when the foals start hitting the ground. For whatever reason, rabicano (a pattern of roan) can have a minimal flaxen affect as well. Insert another wildly nerdy theory here. There's one more way to get a flaxen horse, though this one is incredibly rare, but possible. The gene IS present in the Arab, just in small numbers. I haven't seen it at all, so I can't comment on how it tends to look, but I know what it often does in other breeds. This is the Silver Dapple gene, which does not affect a chesnut horse at all. Its a dominant dilution gene with the same effect eterozygous as homozygous. A black horse with this dilution would appear a flaxen black (look at a Rocky Mountain horse). A bay could be confused with a flaxen chesnut as well - red body, flaxen mane and tail. Sometimes the legs are black, whitening near the bottom, but sometimes the entire leg can be lighter. As you can imagine, these other two won't breed true, and probably are unimportant in the general breeding program, but i had to pipe up. Kris (I can talk genetics all day and enjoy being bombarded by questions) ----- Original Message ----- From: "Diane Trefethen" <tref@xxxxxxxxxxxxxxxxxx> To: <Ridecamp@xxxxxxxxxxxxx> Sent: Saturday, January 07, 2006 12:45 AM Subject: [RC] Palominos A long time ago I read that Palominos don't breed true. The problem is that there are two genes involved in Palomino coloring, or more correctly, two Alleles at the Cream locus. A Palomino has Allele C and Allele C[Cr] where C = normal color and C[Cr] = Cream color. Each parent can only contribute one Allele. Half the time a Palomino will contribute C and half the time C[Cr]. When you breed two Palominos, C-C[Cr], the statistical probabilities are C-C (25%)=normal color, C[Cr]-C[Cr] (25%)=Cream color, and C-C[Cr] (50%)=Palomino color. For more than you want to know about color genetics see: http://www.vgl.ucdavis.edu/~lvmillon/coatcolor/coatclr3.html#fig2a While a C-C[Cr] could be considered the only "true" Palomino, the only two Palomino registries I could find in the United States will both register on just color as is evidenced by BOTH accepting purebred Arabians. As Dawn has noted, an Arabian cannot have the C[Cr] Allele, aka "dilute gene", therefore, the horses both registries are accepting must be chestnuts with a) body color that falls within the acceptable limits for registration as a Palomino and b) flaxen manes and tails with no more than 15% colored hairs interspersed among the white/silver hairs. The two registries are: Palomino Horse Association Route 1. Box 125 Nelson, MO 65347. and Palomino Horse Breeders of America, Inc. 15253 E. Skelly Drive Tulsa, OK 74116-2637 As noted above, breeding a Palomino to another Palomino should result in only 50% of the foals being Palomino. On the other hand, both chestnut coloring and flaxen mane/tails result from recessive genes so if you breed two flaxen maned chestnuts, the result, barring mutation, will always be a flaxen maned chestnut.* *http://www.mustangs4us.com/Horse%20Colors/recessive_color_genes.htm http://www.mustangs4us.com/Horse%20Colors/palomino_or_flaxen_chestnut.htm =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= ----- Original Message ----- From: "Diane Trefethen" <tref@xxxxxxxxxxxxxxxxxx> To: <Ridecamp@xxxxxxxxxxxxx> Sent: Saturday, January 07, 2006 12:45 AM Subject: [RC] Palominos A long time ago I read that Palominos don't breed true. The problem is that there are two genes involved in Palomino coloring, or more correctly, two Alleles at the Cream locus. A Palomino has Allele C and Allele C[Cr] where C = normal color and C[Cr] = Cream color. Each parent can only contribute one Allele. Half the time a Palomino will contribute C and half the time C[Cr]. When you breed two Palominos, C-C[Cr], the statistical probabilities are C-C (25%)=normal color, C[Cr]-C[Cr] (25%)=Cream color, and C-C[Cr] (50%)=Palomino color. For more than you want to know about color genetics see: http://www.vgl.ucdavis.edu/~lvmillon/coatcolor/coatclr3.html#fig2a While a C-C[Cr] could be considered the only "true" Palomino, the only two Palomino registries I could find in the United States will both register on just color as is evidenced by BOTH accepting purebred Arabians. As Dawn has noted, an Arabian cannot have the C[Cr] Allele, aka "dilute gene", therefore, the horses both registries are accepting must be chestnuts with a) body color that falls within the acceptable limits for registration as a Palomino and b) flaxen manes and tails with no more than 15% colored hairs interspersed among the white/silver hairs. The two registries are: Palomino Horse Association Route 1. Box 125 Nelson, MO 65347. and Palomino Horse Breeders of America, Inc. 15253 E. Skelly Drive Tulsa, OK 74116-2637 As noted above, breeding a Palomino to another Palomino should result in only 50% of the foals being Palomino. On the other hand, both chestnut coloring and flaxen mane/tails result from recessive genes so if you breed two flaxen maned chestnuts, the result, barring mutation, will always be a flaxen maned chestnut.* *http://www.mustangs4us.com/Horse%20Colors/recessive_color_genes.htm http://www.mustangs4us.com/Horse%20Colors/palomino_or_flaxen_chestnut.htm =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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