Uncovering Merle
Normally my dog’s paw pads are dark, i.e. dirty. They’re not dirty in the sense that she marks the floor everywhere she walks. We just can’t scrub her paws every time we take her out. So after her swim, I figured it would be a good chance to take a photo so you can see what is Merle in dog paw pads.
Merle is a coat pattern in dogs, not a color of coat. It can affect their paw pad color, as shown in my dog below. Merle is not to be confused with heterochromia, which is specific to the eyes. http://goo.gl/K4Djj
Merle is actually a heterozygote of an incompletely dominant gene. If two such dogs are mated, on the average one quarter of the puppies will be “double merles”. A phantom merle is one with such small patches of merle—or none at all—that it appears to be a non-merle. In America, a dog with the phantom merle coloring is described as being “cryptic for merle.”
Read more in the Wiki: http://en.wikipedia.org/wiki/Merle_(coat_colour_in_dogs)
#ScienceSunday curated by Allison Sekuler Rajini Rao Robby Bowles and me.
July 7, 2013
Thanks for sharing! I love teaching my students about genetics in ways they can relate to, and most of them have dogs. There’s only so much interest I can garner when talking about pea plants.
July 7, 2013
Is it allowed in your place to breed merle x merle? Parts of the 25% homozogote will be deaf (at least 85% deaf), therefore in germany this is not wanted (animal welfare act). (no, I don’t think it’s heterochromia)
July 8, 2013
You are welcome Shannan Muskopf. I don’t know the answer to that Brigitta Blume, I’m a scientist not a breeder. I don’t think it’s against the law but I’d have to search to find out.
July 8, 2013
Chad Haney Thanks for your answer! The regulations for what is called “qualzucht” (i found no translation, word for word it will be “pain breeding”) is also rather new in our laws, mainly based on the “green movement” and the animal rights groups, and not in every case based on scientific research: they also wanted to stop the breeding of chickens and cows. As one of the results of such laws the information and even fundamental research is going rather down over here 🙁
June 9, 2015
Brigitta Blume
Amongst breeders, it is not done. It is considered quite nethical… unethical… (Sorry, glitch. The text won’t let me re edit?)
June 9, 2015
Unethical, unregistered, ‘backyard’ breeders and ‘puppy mills’ will do it, but the pups end up in rescue or killed. I’m for such legislation.
June 9, 2015
Thanks for answering such an old post rare avis.
June 9, 2015
Chad Haney
Is that bad netiquette? I never know… I was drawn here by the lovely dog photos! I didn’t realize how old it was, sorry …
June 9, 2015
No wrong doing rare avis. I copied the post to my #ScienceEveryday collection then I copied it to my dog Collection to see what would happen. So it’s like a new reshare of an old post. No worries.
June 9, 2015
Gretchen S., we were talking about breeding on the OP.
June 9, 2015
It’s not considered responsible to breed deaf/blindness linked recessives in the US if the cross can result in a double recessive. I don’t think it’s outright illegal but it’s definitely disreputable and may result in issues with the AKC, which Americans would need to register purebred dogs with. While I might rescue an irresponsibly bred double merle with the help of a rescue organization I would never purchase a dog, merle or not, from any breeder who breeds merles together. (Or analogous dilution genes like palomino horses, which also need care in breeding.)
So a non-merle is MM, merle is Mm, and double merle (linked to deafness) is mm. Responsible breeders will use an MM and Mm parent, resulting in 50% MM and 50% Mm and no mm.
June 9, 2015
As rare avis mentioned, only backyard breeders would likely breed two merles. Certainly a reputable breeder would not risk their reputation.