Monday, September 10, 2012

Guess the Genotype #87

Can you guess this dog's genotype? Its breed? You might be surprised.

Images were provided to me by Rachel H.

Gromit is a border collie, and I left one picture out before the break because it reveals an interesting surprise you might not expect from seeing the rest of the dog: Gromit is a tricolor.

Look at that foot!
It's not that uncommon for dogs to look quite different depending on the angle, and Gromit is one of them. Though at certain angles he looks like a solid liver, commonly called "red" in the breed, he isn't. I was told his tan points were more prominent when he was younger. I managed to track down some pictures, and it's very true! So, what's his genotype?

To begin, Gromit must be atat tan point. Recessive black does not appear to be in the border collie breed, so he should not be a carrier.

Next, he is obviously liver. All livers must be bb liver.

The red in his coat is moderate in intensity. Going with the theory that the Chinchilla locus controls red intensity, this should make him cchcch moderate red.

Gromit also has a mask. This, combined with his white markings, is what makes it so difficult to tell he's a tricolor. This mask is quire extensive, obscuring his "pips" (the tan above the eyes) and nearly all of his cheek markings. From what I can find, there are more borders without masks than there are with masks. Because of this, I suspect Gromit is EmE masked carrying non-masked. It could be possible he carries recessive red, but considering the fact that it isn't that common in the breed, I find it unlikely.

The white on this dog is very typical of border collies, and is the amount of white most people think of when they hear "border collie." This is Irish white, which would make him sisi Irish white.

Lastly, Gromit has ticking. It isn't very dense, which makes me suspect he is Tt ticked.

So, that's atat bb cchcch EmE sisi Tt or masked liver tricolor with ticked Irish white.

Something I did not discuss previously was a question posed to me by the person who sent me the images. Could he be a merle? He does have a small blue spot in his left eye, and his father was a merle. There is a small possibility he is and that whatever merling he has may be obscured by his white markings. However, cryptic merles of this sort are very unusual. It's more likely that he is simply missing some pigment in his eye for another reason. This can happen in dogs with white, though it is usually seen when the white markings touch at least one corner of the eye. I have seen dogs marked very like Gromit with a similar blue eye spot, and those dogs were from breeds that do not have the merle gene (like this basenji). It's very possible that the spot is related to the white spotting gene, or it could be from something else. It's difficult to say.

1 comment:

  1. Fascinating! Thank you for using Gromit -- I learned a lot, especially about masks. I wonder what tipped you off that he has a mask? Is it just the obscured tan points, or something else? Is the mask a darker shade of liver, or the same shade as the rest of his coat?