Friday, July 29, 2011

Guess the Genotype #11

Can you guess the genotype of this dog?

Image is from Wikimedia Commons under a creative commons license

Read more for the answer...

This is a "blue roan" English Cocker spaniel. I thought the long grass and angle of the face might make it look like an American Cocker and possibly even a merle one at that. What makes a blue roan? Let's break it down:

Despite what the name implies, this is actually a black dog and as such is DD non-blue for the  dilution gene. Blue dilutes do not appear to occur in English cockers.

Red in English cockers is usually recessive ee red. Though blue roan is the most common breed color, it is very possible this dog carries recessive red. I am assuming it is Ee normal coloring carrying recessive red

Since this dog is black, it is most likely KK, Kkbr, or Kk. Since brindle does not occur in cockers, that eliminates the presence of the kbr gene. Sables do occur in the breed, though rare, and as such I am assuming this dog is KK black.

Though there is some debate as to the exact nature of the relationship of ticking to roaning, including whether or not they are associated with separate genes. However, recent studies have found that roaning is caused by a dominant gene in English cockers. Non-roan dogs are unusual in English cockers and as such this dog is likely RR roan. Because of the nature of the roan gene, this dog will have been born white with black patches! The spots and flecks come into the white later, which are what give the dog a gray coloring.

This dog is a piebald, and as such is spsp piebald white spotting. Extreme whites do appear to occur in the breed, but not very commonly and as such I am assuming this dog does not carry the gene.

So, that's DD Ee KK RR spsp or piebald black roan aka "blue roan."

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