Dominance heirarchy?

[allison]

I studied Biology (even have an MS) but have been out of school a long time. Recently I got a pup from a friend's litter that made me think about genetics. The father is a purebred Karelian Bear Dog (KBD). The mother is a Golden Retreiver (GR) that supposedly also has some husky although you can't tell- she just looks like a golden retreiver but with a slightly different body. None of the puppies look like a golden retreiver at all. Five of them look just like baby Karelian Bear Dogs. One of them (mine) looks a little bit like a Karelian Bear Dog and a little bit like a husky. Mine is a girl. There is one other girl and four boys.

My question is- with the way the pups look it is tempting to assume that the alleles from the parent KBD are dominant over GR for several genes that control appearance including color, ear shape, tail, etc. BUT my dog looks like a Husky (H!). If GR is dominant to H and KBD is dominant to GR, does it follow that KBD is dominant to H or could H be dominant to KBD? I realise there are multiple genes at play, which might makes things complicated in this particular example. But the simpler version of the question is still on my mind-

 

If allele A is dominant to allele B and allele B is dominant to allele C, can you predict the dominance relationship between A and C? It's been a long time since I have cracked a textbook.

 

Thanks- would appreciate some assuaging of my curiosity!

 

PS- Just because I am a proud mama at the moment I attached my dog's picture.

 

 

[Geshenk]

In answer to your last question, yes, A would be dominant to C, but you're correct in that this is over simplification. There is no one gene that defines any breed of dog.

 

Most breed characteristics are not very obvious in young puppies as these tend to develope as the dog matures, and this is particularly true of body morphology. Coat type and colour are though exceptions to this so this does tend to influence perception of breed type in puppies.

 

KBD short coat type is dominant over GR long coat, so the puppy is short coated carrying long (assuming the GR cross is long coated). The colour is not quite so simple. Assuming the GR parent is normal GR colour, this is recessive ee, yellow. KBD colour is black & white and as black is dominant, and as this is the only colour in the breed, the sire would be expected to be homozygous KK EE, in which case, all pups should have been black. Your pup looks to be sable & white (with black mask), which shouldn't be possible but it could possibly be a rather pale seal, genotype heterozygous Kk Ee. If she is sable, then she will get gradually lighter in colour (except for the mask) and might even end up clear pale sable, a similar colour to GRs. If she is seal, she will stay the same or may get darker.

 

White spotting is a bit more complicated as there is co-dominance and possibly more than one gene involved, but generally less white is dominant over more white. Quite possibly the GR parent carried for white markings from the Husky input.

 

Other charcteristics like ear carriage/type, body type, tail etc are each controlled by multiple genes so very difficult to predict. I do agree though that the general appearance from the photo seems to be of spitz type and this could be down to the Husky input doubling up with KBD alleles. KBDs and Huskies are both spitz breeds and very similar in coat, tail, ear and general body type.