colouring

Comments

• WrylyBrindle

  May 2009 edited November -1

  I don't know, but I look forward to those who DO know chiming in on the passage of brindle genes. "Brindle is Best" in my book!
• ayk

  May 2009 edited November -1

  It's not quite correct that any litter, regardless of the color of the parents, can produce any color. It depends on the genetic make-up of each parent.
  
  There are several genes speculated in the Japanese Akita. Just for kicks, I'll just list them even though I won't use them in the explanation:
  
  Ay = agouti yellow = gives rise to outwardly red Akitas.
  
  Kbr = brindle = dominant gene that adds stripes to a coat.
  
  e = recessive yellow (white) = recessive gene that removes all pigment from a coat. Even individual hairs/whiskers are turned white.
  
  cch = theoretical chinchilla-dilute = partially recessive gene that lightens red in a coat. Should still be able to see black hairs somewhere on the body.
  
  -------------------------------------
  
  A white dog always carries the potential for red color, but won't necessarily carry the potential for brindle. You can't really tell by looking at the dog, but can guess based on whether the dog's ancestors were brindle or not.
  
  A red dog does not carry brindle at all, but could be carrying the potential for white.
  
  ----------------
  So, a red dog mated with a red dog should never produce a brindle dog. They could produce a white dog though.
  
  A white dog mated to a white dog should only produce white dogs.
  
  
  A red dog mated with a white dog that does not carry brindle will never produce brindle.
  
  A red dog mated with a white dog that does carry brindle could produce a brindle.
• miss_mallinson

  May 2009 edited November -1

  my biology lessons from school just flooded back to me. Thanks for responding to the question! It was very helpful :D
  
  and yes, wrylybrindle, they are best - I think :D
• WrylyBrindle

  May 2009 edited November -1

  If anyone knows about brindle in Kai Ken- that'd be cool too. Akatora, Chutora, Kurotora... and what's with those cream kais I have seen photos of? Which brindle is dominant? Is akatora recessive? and isn't it so hard to tell since they tend to be born dark and brindle up as their coat cycles through shed seasons and matures? My guy's only HALF-Kai, so his coat is pretty much the same color as when he was a pup. Are akitas ever red or black brindle? I think I have only seen silver brindle akita...
• ayk

  May 2009 edited May 2009

  I'm a bit weak on Japanese descriptions matching up with photos.
  
  Akatora is this dog? Red-brindle?
  
  
  Kurotora is this dog? Black-brindle?
  
  
  And Chutora is in the middle range?
  
  Do the cream Kai have black whiskers? I can't tell in the pictures. That'll help narrow down the genetics.
• WrylyBrindle

  May 2009 edited November -1

  Yes, that's right- akatora =red brindle and kurotora= black brindle. Chutora is "medium brindle".
  I dont know anything about those cream kais- except having seen the same photos you have probably seen.
  Most kai in the US seem to be kuros and chus...
  
  Walrus' Haru is a really nice red one.
• ayk

  May 2009 edited May 2009

  Well, here my theory behind the Kai's brindle strips (or lack of). I haven't traced any family lines to see if the theory is correct or not.
  
  The Kai has a base coat of red, the same as the Akita but without the urajiro. All Kai are homozygous for Ay.
  
  On top of that red coat is the black patterning. Some geneticist recently confirmed that there are three alleles at the K loci. They don't really know what modifies the pattern so that it looks different from breed to breed though. (Akitas usually have thin stripes, Kai have thicker stripes.)
  
  Strength or dominance falls in this order:
  
  K > Kbr >ky
  
  
  K = dominant all black
  Kbr (or kbr)= less dominant black strips
  ky = recessive normal color (no added black)
  
  This is for dogs in general.
  
  
  I used to think the stripes on a Kai were caused by the following combinations:
  
  K K = very black kurotora with really no stripes
  K Kbr = kurotora with faint stripes
  Kbr Kbr = chutora
  Kbr ky = akatora
  ky ky = "cream" Kai,
  
  but I'm moving away from the ky ky assignment as I found a picture of a cream newborn puppy and it does not fit the ky ky model. Rather, it seems to be a caused by ee.
  
  
  Instead
  I am thinking that things have been tweaked for the Kai.
  
  K* = dominant, mostly black (*only found in Kai)
  kbr = "recessive" brindle
  
  
  And then this would be the assignment:
  
  
  K* K* = kurotora
  K* kbr = chutora
  kbr kbr = akatora
  
  
  and for our special cream Kai situation,
  
  E = normal color
  e = recessive yellow (visualize Labradors)
  
  This ee couldn have been contributed by the other Nihon Kens but somehow it lost the modifier changing yellow to a whiter color.
• WrylyBrindle

  May 2009 edited May 2009

  hmm... Can an akita have urajiro AND brindle? Brindle OVER a red urajiro base- so that the stripes continue from the red or blue into the lighter cheeks and belly and legs?
  for example, I think that in mastiffs you can have black mask factor AND brindle at the same time...
  
  (and thanks so much for sharing your knowledge!!)
• ayk

  May 2009 edited May 2009

  Yes, an Akita does have urajiro and brindle and the brindle does go over a red (and white) base.
  
  Here is an example of one that has very dense stripes, but you can still make out the red and the urajiro.
  
  
  The thing is, the dog also has white-spotting which is different than urajiro. White-spotting blanks out everything (or nearly everything except ticking). Same dog:
  
  
  
  Here is another excellent example, posted by Bars on this forum.
  OUKA HIME go di Casa Saporito - Megapolice Style kennel
  
• WrylyBrindle

  May 2009 edited May 2009

  So the white spotting doesn't count, right? Because it "covers up" both brindle AND urajiro?- what I should notice is the red behind his ears and forehead and that his muzzle and cheeks have no red?
  
  Is that what this is? Red on the back, shoulders, ears and top of the snout and head, white on the cheeks and undersides- but brindle overall? You can have both...
  

  
  
  
  
  

  
  
  If you took off the red stripes, he'd be red with white urajiro?
• ayk

  May 2009 edited May 2009

  Yep, you've pretty much got it, except in the last sentence. If you take out the BLACK stripes, he'll be red with urajiro.
• WrylyBrindle

  May 2009 edited May 2009

  Oops- you are right, that is what I meant!
  
  and there is no urajiro in kais, or can it be there but the brindle is just so thick you'd never see it? The Akatora above is all red underneath.
• ayk

  May 2009 edited November -1

  There's no selection for urajiro in Kais. I don't remember where I read it, but white peaking through is not favored for them.
• TheWalrus

  May 2009 edited November -1

  I have asked around in the past, and it seems no one has done any genetic testing on the Kai yet. It's something I'm interested in, and it's a project I'll probably get around to working on sometime in the future.
  
  There are quite a few people I know that are interested in the testing, so I shouldn't have any problem getting samples. The breed standard for the Kai demands brindle. Of course there are the rare whites, and I've seen several solid blacks. I've also seen quite a few with white chest patches.
  
  I've had old timers tell me that breeding aka-tora to aka-tora many times results in undesirable traits such as:
  -loss of brindling
  -thinning of the red in progeny's coats
  -softer coats
  -shorter coats
  
  Obviously with proper genetic testing you could solve these issues and figure out a better way of preserving quality reds.
• ayk

  May 2009 edited November -1

  Very interesting!
  
  When they say loss of brindling amoung aka-tora x aka-tora, is it complete loss of brindling or just a reduction?
  
  When they mention thinning of the red, are they referring to red coat color or coat texture/density?
• WrylyBrindle

  May 2009 edited November -1

  If all kai are red underneath, and red brindle vs a black brindle is just that red brindle has less stripe density than black, then maybe it makes sense that an accumulation of "less stripe density" (akatora is not dominant over kuro, right?) factor over generations could result in dogs with much fewer stripes...does that work out? Akatora is eventually cumulative?
  
  if I can continue to roll this snowball...
  
  Is urajiro pattern the same gene (or allele?) in a shiba, an akita, a coyote, a malamute? etc? Or is urajiro expression a combination of several alleles? Black mask is its own thing, but I dont know if urajiro is...
  
  Is a black and tan shiba a black shiba with urajiro, (maybe he is tan and not white because his pigmentation is darker overall?) or is it the same b/t pattern like to other black and tans, like rottweilers? (not that shiba are related to roots, just that urajiro must be an available pattern in canids other than nihonken?) Urajiro has light bellies, right? But dobes and rotts do not- so is it correct to say that b/t has no relation to urajiro patterning? Its the same areas of the face and legs- or maybe I need to look closer...
  
  "Dammit, Jim, I'm an artist, not a geneticist!"- Ayk will set me straight...
• Calia

  May 2009 edited November -1

  With a Black and Tan shiba, there is urajiro but not quite the same as rotties and dobies. Often times, a rottie and Dobbie coat is refered to color with rust (black with rust, chocolate with rust) as it refers to a solid color with brown in the legs chest and spots over the eyes.
  
  Urajiro is a given for shibas, and has to be there no matter what the color (this is why creams are not accepted colors), thus why we call it a black and tan (not a tri-color) or red (not red and white).
• ayk

  May 2009 edited May 2009

  Well, that's my ongoing theory about red brindle vs. black brindle. Like I said before, I haven't had the opportunity to see if it matches up with lineages.
  
  Your latter statement about black/tan being separate from urajiro is the current thought among color genetic fans. If you look closely at it in Shibas, the white urajiro is greater on a red Shiba than the tan/white pattern on a black/tan. (White going up the throat on red Shibas while black/tan only have a tan/white bowtie on the chest.)
  
  Black/tan is known (on the same loci as Ay), but urajiro hasn't been pinned down yet. Urajiro is found in other animals like the horse and the mouse, but it might or might not be the same cause. It is probably the same in different dog breeds though.
  
  What is more certain is something called domino. You might have noticed that the urajiro on a Shiba is usually different than the urajiro on a Japanese Akita? The Shiba usually has a mask going under the eyes and on top of the snout while a Japanese Akita has either noticable white spots above the eyes or, for lack of a better descriptor, a white unibrow? Sometimes the JA has a small blaze up the forehead? This additional white is believed to be caused by a recessive gene called domino and is also found in Malamutes.
  
  
  Now, I'll throw in a curveball to the case of black/tan and white countershading. There used to be some people that believed cream was linked to urajiro. I think they were confounded by a dog like this one (I had a Shiba example, but my detachable harddrive is not working):
  
  
  What caused this particular dog's appearance was black/tan + a gene that removed red coat pigment. Whether the dog has true urajiro or not can't be seen. This red-removing gene also gives rise to pale red dogs and creams with black hairs.
  
  It makes sense that the Japanese would be against a black/tan with no red edges in the urajiro as it'll encourage the production of less desirable colors in their Shiba.
• WrylyBrindle

  May 2009 edited November -1

  Agouti is a descriptive coat trait for malamutes, elkhounds, mice, and many mammals. Are black and tan, or urajiro variations of agouti? OR maybe I have this wrong and agouti is banded hairs, like brindle and sable, wolf grey?
• ayk

  May 2009 edited May 2009

  The term agouti is used alot so I couldn't attest to how it's used in each individual species or breed.
  
  AFAIK, I believe the wild-type grey color, as found in wolves and mice, was first called agouti, and then the location of the gene was named the Agouti loci. The agouti color gene is designated A (indicating wild-type) or Ag (to clarify the color more).
  
  "Red" and black/tan genes are located on the Agouti loci. Hence, the two genes have the designation Ay and at.
  
  Wolves do have a bit of a ventral lightening, but it's not nearly as intense as in the Japanese breeds. Calling urajiro a variation of agouti doesn't seem right, but as we don't know what causes urajiro, who knows?