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I'll be looking at the puppy to begin with. The puppy's name is Lizzy and she is a German shepherd mixed with a Doberman pinscher. You can definitely see hints of both breeds. Her genotype is quite simple: she is expressing the tan point gene and that's about it. This coloration is seen in both Doberman pinschers and German shepherds. This makes her atat tan pointed.
As for the adult dog, his name is Jack and he is believed to be an interesting sort of mix: AfriCanis, Belgian shepherd and Catahoula leopard dog. I honestly doubt that this is what his true mix is. The AfriCanis is basically the village dog of southern Africa. There isn't a great deal of resemblance between Jack and the AfriCanis, which is a mostly larger, smoothly coated group of dogs. In my opinion, I find it more likely that his appearance is due to mixing with some sort of spitz breed. It is quite possible that he is a a spitz mixed with some sort of collie and shepherd. This could explain basically all of his traits, including the curled tail and markings. Despite this, the owner implies that the mix described earlier is a known mix: the father being an AfriCanis and the mother being the Catahoula/Belgian shepherd. Anyway, on to the genotype:
Jack is saddle marked. Though at first glance he appears to be sable, but he is, in fact, not. For one thing, as a puppy his markings were more similar to a tan pointed, dog, which is to be expected in saddle-marked dogs. The dog starts out with a lot of black, which shrinks with age. Since he is believed to be part Belgian shepherd, it is very possible that his shepherd ancestor was recessive black. However, I suspect what his saddle markings came from the believed Catahoula ancestor, which would mean the recessive black didn't pass on. I suspect that his supposed AfriCanis ancestor was tan pointed. Though testing has shown that tan point and saddle marked are caused by the same gene, some sort of modifier acts to determine the amount of tan and saddle still seems to be dominant to tan point. As such, it is most likely, in my opinion, that Jack is asat black and tan (saddled carrying tan point).
I chose this picture over some of the others of Jack since it makes him look liver in comparison to his friend Lizzy. However, he is in fact black. It is possible that he carries liver since the Catahoula, if not others, are known to sometimes come in liver. Despite this, I suspect Jack is BB non-liver.
Next, the red is Jack's coat is really quite dark. I find it most likely that he is CC dark red.
Lastly, this dog is clearly expressing the merle gene. He is unusual in that he is a saddled merle, however the merle gene is there just the same. This would make him Mm merle.
So, that's asat BB CC Mm or dark red with a merle saddle.
kelpies?
ReplyDeleteOne's a Doberman pinscher/German shepherd, and the other is believed to be an AfriCanis/Belgian shepherd/Catahoula leopard dog.
DeleteA quibble: according to the black and tan and saddle tan paper by Dreger and Schmutz, all the saddle tan dogs that were genotyped were at/at. IOW, saddle tan is black and tan with the expression being changed by an unknown modifier.
ReplyDelete"Exploration of potential modifier genes of ASIP may explain the variation seen within ASIP alleles, such as at/at saddle tan and the grizzle/ domino phenotype in Afghan Hounds and Salukis that results from an interaction of MC1R and the at/at ASIP genotype (Dreger and Schmutz 2010)."
I have pictures of a saddle tan Saluki, with black mask, that has been genotyped as at/at, B/B, EM/EG, ky/ky. Saddle tan is not contained on a separate allele from black and tan. I wouldn't want to speculate from a single example, but I find it interesting that this dog also has EG, which we know modifies the expression of black and tan into grizzle/domino. Unfortunately the dogs in the study were not genotyped for the other locuses (locii?)
If I wanted to speculate rather wildly, I'd guess that we are looking at different versions of EG, much like there are different versions of 'a' and different versions of 'b.'
Oh, I know. I've been maintaining the old theory that they are separate Agouti alleles since they are different but the reason why has not yet been identified. It's in some ways the same reasoning behind my inclusion of the Chinchilla locus as it pertains to red pigment, even though its action in dogs is purely theoretical and has, as of yet, not been confirmed. I might go back to dropping the theoretical loci, but some of them (like progressive greying) have a lot of support for their theorized mode of inheritance.
DeleteIt would be curious if there were modifiers that affect grizzle as well as tan point. Since the genes are connected, its makes this even more intriguing.
I would be quite curious to see that saluki, by the way.