Japanese Akita Coat Colors and Genetics [INFOGRAPHICS]
I've been working on these aids for educational purposes. I started out doing some genetics stuff, but got sidetracted by making variations on color/pattern cause it was fun. Also because @timkim didn't like that I was using a medium red brindle as the example for brindle, and he wanted me to use a black or silver one... lol.
And this is a work in progress preview of the next part... I'll be making a bunch of punnet squares. Oh boy, fun!
NB: I decided to refer to brindle as K instead of kbr for two reasons. First, because of the article posted a while back indicating that K (black) may actually be expressed as brindle in Akitas. Second, because it is easier to read and understand this way; the letters were visually lost in the brindle pattern. Likewise, I know that the k (non-solid black) gene does not directly cause red, but for all intents and purposes within the breed, it is red.
And this is a work in progress preview of the next part... I'll be making a bunch of punnet squares. Oh boy, fun!
NB: I decided to refer to brindle as K instead of kbr for two reasons. First, because of the article posted a while back indicating that K (black) may actually be expressed as brindle in Akitas. Second, because it is easier to read and understand this way; the letters were visually lost in the brindle pattern. Likewise, I know that the k (non-solid black) gene does not directly cause red, but for all intents and purposes within the breed, it is red.
Comments
Great work though! If you want help with that I know one really good expert on dog color genetics, Liisa Sarakontu She can help you on this.
More expansive explanations are already available on the web that include stuff which applies more globally across the dog breeds. ie. http://www.doggenetics.co.uk/
Japanese Akitas are all homozygous AyAy so every JA that has kk will be sable (red). Therefor all we have to be concerned with is the K Locus.
This is a really great infographic! Good job!
Brindle by K Locus (dominant gene)
But there is no scientific proof for the exact location of the white gene in japanese dogs. White is always a extreme dilution in japanese dogs and never a pure white as we can see on S Locus. Recent researches tend to say that it is not on the E Locus but in another one. However, it works the same way as describe.
But I'm not agree with your "dilution", because there is no dilution gene in Akita. Brindle is always black, never blue (genetically). It's the position of the stripes and the intensity of the red which make the fur look like blue... But it is not.
Here is an example of a pale red JA who has little/no pheomelanin but still has black whiskers. What causes this pale red hasn't been pinpointed to a locus. Some people have started to refer to it as the theorized I locus. It's akin to the greys you see in Siberian huskies - something washes out the red pigments but leaves behind the black pigments.
I thought there was research literature about the "e" in JAs? But I do know that @poeticdragon did DNA test her white JA and a friend's known white carrier as a control to see if the "e" test works or not. I think I challenged her to a bet on this. :-D
The "e" does apply for her population.
We can't make the mistake when seeing the dog as puppy : it's completely different.
I would like to do tests on my own dogs (I have a white carrere male). Someday maybe.
There are some lines about that here : http://www.doggenetics.co.uk/albino.html
I have my own theory about color intensity. But quite hard for me to explain in english.
But one thing is sure : Color's Locus only determine the main colour. Variations are determined by a lot of other genes.
Not in Akita, but in Shikoku ken, we have some surprises with testing color !
http://www.ncbi.nlm.nih.gov/pubmed/21321476
They mention the mutation "R306ter in the MC1R gene", also known as the "extension" locus.
The full article is very interresting... So... you are right for the E Locus My fault :P
My malamute friend and I believe the existing agouti series test offered by various labs is not specific enough to determine between agouti (ag) and black/tan (at).
A dozen of Shikoku dogs was tested for the Agouti Locus. And we have various results :
aw/aw (ok, black sesam dogs)
Ay/aw => Black sesam and sesam dogs
Ay/Ay (!!!) => sesam dogs (quite dark...)
Probably japanese sesam color have a specific allele.
On the other hand, I am pretty sure that my American Akita who is white is NOT e/e. I think she is extreme spotting. Or maybe she's both. But I haven't tested her (no reason to).
@poeticdragon : You did a great job with your testing. And I'm happy that somebody does it.
really great read and thank you for doing this great job!!!