Gifted Issues Discussion homepage Forums General Discussion Help me with my genetics -- a bit OT!

Sorry for the off topic post. If it's a problem, I can delete. I'm hoping that someone here has some expertise in genetics.

We have this cute little mixed breed dog who has been the source of numerous conversations about her potential breed. So, the kids got a dog DNA kit from Bianca, the dog, for Christmas. You swab the cheek and mail it in to the manufacturer and they tell you what breeds your dog has in it.

Here are some photos of Bianca:
Bianca #1

Bianca #2

She weighs about 45 lbs, is very short haired, and has one eye that is green and the other that is half light blue and half hazel. I got this breed report back telling me that she has two "intermediate breeds" -- meaning that she is at least 25% of each these breeds and numerous breed traces that are too small to be showing up. The intermediate breeds are.... Chow chow and giant schnauzer -- both 80 lb. hairy dogs.

I emailed them some photos of Bianca and told them that the test either was not very accurate or they mixed their samples. They sent me a long email trying to explain genetics and how two brown eyed people could have a blue eyed child, etc. I know that much about genetics at least! They also said that she definitely had one grandparent who was a pure bred chow chow and one who was a purebred giant schnauzer.

The issue I have, other than she doesn't look a thing like either of these breeds, is that these large dogs would have had to have bred with something the size of a jack russell terrier to produce a dog the size of Bianca. I'm kind of surmising that this might have killed the mama dog if she was the small one or that the papa dog would have a hard time mounting the big female if he was the little guy.

What do you think? From a genetics standpoint, could Bianca be 50% large, hairy, bearded, purple tongued dog? Incidentally, you cannot see in the photos, but she had very light pink lips and a very light pink tongue.

What traits are dominant for dogs? For instance, brown hair and brown eyes are dominant for humans. Is dark hair/coat also dominant for dogs?
If so, I suppose your dog could have recessive traits being expressed.

Sorry, that's the extent of my knowledge...

Here's something on coat color genetics...

http://bowlingsite.mcf.com/GENETICS/ColorGen.html

also chimerism might be something to consider, but only if you have about 40 years.

http://en.wikipedia.org/wiki/Chimera_(genetics)

Well I know nothing about dog genetics but I am a very long time dog owner and I have studied lots of breeds. My un-scientific guess is that she looks like yellow labrador and bull terrier :-)

My understanding from long ago biology classes was that it wasn't actually as simple as dominant brown/recessive blue. There are apparently dilution genes that can turn a brown eye hazel, for instance. Green can be a variant of brown or blue as well I believe, but don't quote me on that!

White coat is a recessive gene kind of how you can get a white boxer from two parents who are not white. Both parents need to carry that gene, though, for one of the puppies to come out white.

Here's where my skepticism comes in even with my rudimentary genetics understanding:

Option A
Parent #1 is half chow/half giant schnauzer
Parent #2 is multi-breed mutt

Parent #2 could certainly carry recessive white coat genes and eye genes that would dilute brown to green or gold (like one of her eyes).

Parent #1 could not have these recessive genes, though, b/c I don't believe that either chows or schnauzers carry recessive eye or coat coloration genes that would result in a white puppy with bicolored eyes.

Option B
Parent #1 is half chow/half multi-breed mutt
Parent #2 is half giant schnauzer/half multi-breed mutt

Both of the parents would need part of their multi-breed mutt to be made up of siberian husky, aussie, or some other dog with the bi-colored eyes and both would need have mutts with recessive white coated genes. The chance that this happened and they both passed those recessive genes only on to Bianca seems kind of slim to me. Both parents' pure bred halfs also must have mated with some really small dogs to get a dog her size. This seems like a lot of happenstance to me.

Thanks. This does look complicated!

CAmom, we've thought about those breeds as well. We've also considered siberian husky given her eyes, various terriers, viszla, albino doberman, pharoah hound...

The green/hazel eyes in humans comes from what is called mixed dominance or co-dominance, seen usually with one brown-eyed parent and one blue-eyed parent. In other words, in some people, brown is not completely dominant, but can share dominance and create an intermediate color. This is also the principle behind Gregor Mendel's pink flowers obtained from red and white parent flowers.

Coat color in dogs is apparently very complicated, because of multiple genes and two different types of melanin.


Is white recessive in dogs? I guess you'd have to know more about the characteristics of the four genes' expressions. Or have experience breeding dogs.

That's what I thought from the reading I had done, but I could be mistaken.

Her size and short hair add to my confusion about those breeds. Dh did have a border collie mix with short hair, though. Her other two breeds were pit bull and lab however and she did have some definite border collie markings at least.