Wednesday, August 13, 2014

Guess the Genotype #90

I'm going to be working on catching up on my lengthy backlog of GtG requests and suggestions.

Can you guess this dog's genotype? Its breed? Click read more to see my guess.

Images were provided by Lisa at San Antonio Pets Alive!



Margaux as a puppy
This is Margaux, a great Dane with a rather unfortunate start to life, having lost her mother at only a few days old. Fortunately, Margaux is now a much loved pet! Her coloring is decidedly unusual, but not outside of what can come from what is seen in the great Dane breed. So, what is Margaux? Though at first glance you might think she's a fawnequin, she is actually a fawn merle with a somewhat unusual trait: the merle extends throughout her red! So, what's her genotype?

As Magraux is a fawn, she is genetically sable. Sable is the dominant-most gene on the agouti locus and other variants of this locus appear to be absent from the Dane breed. As such, this dog must be AyAy sable.

This dog also has a mask, which is a trait preferred in fawns. Great Danes appear to be either fixed or near-fixed for the masking gene. As such, Margaux is most likely EmEm masked.

At least one of Margaux's parents was a Harlequin, and as such there was at least a 50% chance of her inheriting a copy of the dominant Harlequin gene, which is a gene that modifies the activity of the merle gene. Did she? Looking at her coat, her main body is made up of two different shades of red: a darker color that is essentially "average" fawn and a lighter color that is still definitely reddish. If she had received a copy of the Harlequin gene, those lighter areas would have been stripped down to white, but they were not. As such, she must be hh non-Harlequin.

Margaux and two siblings, the only survivors of a litter of eight
Both of Margaux's parents had black-based coats. All of her littermates were either merle or Harlequin, which are also black-based. So, how did Margaux happen? Black is a dominant gene on the K locus, which is also where brindle (kbr) is located. In addition there is a recessive that codes for neither black nor brindle which allows the agouti locus to show through (in Danes, this would be fawn). Both of Margaux's parents must have been Kk (black carrying non-black) to produce a fawn puppy. As such, this dog is kk non-black/brindle.

Though Margaux does not have the Harlequin modifier, she is indeed merle. Due to the lack of white in her coat, she must have inherited only one copy of the gene. As such, she must be Mm merle.

Considering the amount of white that is seen in Margaux's siblings, there is a significant chance that she inherited some variant of the spotting locus. This locus is responsible for the white in mantle or "Boston" great Danes. The preferred amount of white on those dogs is almost always produced by Irish white spotting, and many Harlequins also have this variant due to the color class breeding of Harlequins, mantles, and blacks. This dog does indeed have a small amount of white, including all four feet. As such, it's likely that Margaux is Ssi solid carrying Irish white.

So, that's AyAy EmEm hh kk Mm Ssi or fawn merle (masked sable merle carrying Irish white).

2 comments:

  1. I have a foster with the same markings as Margaux, but sissy isn't a GD. She weighs about 42 lbs. Her littermates don't look like her at all! I am dying to know what her genotype is!

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    Replies
    1. She might be quite similar! Since merle is seen in a number of breeds, your dog could have received a copy from an ancestor who happened to be a breed that is also known to come in merle, such as border collie, Australian shepherd, or Catahoula leopard dog.

      Feel free to share Sissy with me at musingsofabiologistanddoglover@gmail.com if you would like me to do a post about her like I did for Margaux.

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