Thursday, June 20, 2013

Guess the Genotype #89

It's been quite a while since I've done one of these. Part of the reason why is I yet again lost most of the e-mails that have been sent to me by readers. I am going to be hunting for them again, but it's going to take time to find them. To help with this issue, I have a new e-mail specifically for the blog that will allow me to not lose e-mails again.

Anyway, can you guess this guy's genotype? What about his breed?

Image provided by my friend Angela P. Big thanks!

This is Pepper, and according to his owner he's a Jack Russel terrier/rat terrier mix. The first thing you'll probably notice and Pepper's coat is that, though appearing mostly black, he has quite a bit of red in his coat. Unlike sunburning, the red is not most prominent on his back and sides. In fact, it's the exact opposite. His appearance is pretty classic for seal, also sometimes called "bad black." So, what does that mean for his genotype?

To begin, seal is a coloration that allows some of the Agouti locus, which is normally completely hidden by dominant black, to peek through. Since the pattering of seal on this dog is quite reminiscent of sable, Pepper must have at least one copy of the sable gene. His father was also a black and tan piebald, so Pepper must carry the tan point gene. This makes him Ayat sable carrying tan point.

Since Pepper has some rat terrier in him it's possible that he carries either liver or blue, since both colorations appear in the breed. However, he's only 1/4 rat terrier, so I find it most likely that he doesn't. This would make him BB DD non-liver and non-blue.

As for the intensity of the red pigment in his coat, it's difficult to say. Seal distorts the color significantly, making it darker than it would be otherwise. Since Pepper's father was said to have fairly faint points, I'm going to assume that they were dark red with penciling and/or some other obscuring black overlay. His mother was black and white, so there is no way of knowing what genes she carried for intensity of red pigment. Based on the theory that red intensity is controlled on the Chinchilla locus, I am going to assume that Pepper is Cch moderately dark red pigment.

Seal dogs, when tested, have been shown to have at least one copy of the dominant black gene. Whatever causes the gene to not be expressed fully is not yet known. Since Pepper's father had tan points, he must carry non-black on this locus. This makes pepper Kk bad black carrying non-black.

Lastly, Pepper has prominent white markings. His mother has some white and his father is piebald, and as such Pepper must have at least one copy of the piebald gene. The Spotting locus is highly variable and the more recessive genes can influence the amount of white that a dog will have. In boxers, for example, "flashy" dogs have Irish-type white markings due to carrying the extreme white piebald gene. Due to the fairly moderate amount of Irish-type white seen on Pepper, I find it most likely that he is Ssp solid carrying piebald.

So, that's Atat BB Cch DD Kk Ssp or seal and white carrying sable, tan point, non-black, and piebald.


  1. I am very enjoyed for this blog. It help me very much to solve some problems. Thanks a lot for sharing this with all of us. I appreciate it very much! Looking forward to another great blog!

    Kind Regards,

    Colin Seal
    electric dog fence

  2. I didn't realize how long it had been since I dropped by here until I did, and discovered that you hadn't posted anything for over six months. Is everything okay?