Monday, July 16, 2012

Guess the Genotype #82

Can you guess this dog's genotype? Its breed?

Image is from Wikimedia Commons under a Creative Commons license

This is an Australian cattle dog named Mishka. He has a rather unusual appearance for the breed. Generally, the white on the dog will be more evenly distributed and there will be either far more black (making the dog a blue) or far less black (making the dog a red) than is seen here. Figuring out what exactly is going on here is going to be a bit difficult.

First, one big question when looking at this dog is what caused this amount of black? Either this dog is a fairly heavily marked sable, or a lightly marked black and tan, aka saddled. In the breed, saddled dogs are described as having "creeping tan" as they appear to be blue as puppies, but become more red with age. Since this is known in the breed and it's very hard to find a sable that has anywhere near this much black, I suspect this dog is a fairly old dog that has creeping tan. This would make Mishka atat black and tan (saddled tan).

The red on this dog is rather dark, so using the theory that the Chinchilla locus controls red intensity, this would make him CC dark red.

All cattle dogs are also extreme white piebald, which is why they are born almost completely white and have their white areas fill with colored hairs as their age. Due to this, Mishka must be swsw extreme white.

Lastly, it must be determined what made this dog's coat have such patchy white distribution. If you look at some parts of the dog, namely the face and legs, the white appears to be roaned. On the red of the body, it appears to be more like ticking. So, what's going on here? It's believed that roan may be thanks to the the presence of both the ticking gene and a roaning modifier. Both are believed to be dominant, and thus if this is true it would be possible for a normally roaned breed to throw a dog with ticking rather than roaning. Or even a dog with clear white. Clear white has shown up on at least a few occasions in the breed, so it makes me suspicious that at least some cattle dogs carry the recessive non-ticked/non-roaned genes. In the case of this dog, I suspect that the appearance of roaning is due to age, since graying frequently affects both the face and legs. This would mean the dog is simple ticked and not expressing the roan modifier. This would make him most likely rr TT ticked.

So, that's atat CC rr swsw TT or extreme white with saddled red ticking.

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