Zidane vom Haus Sevens - homozygous sable? - Page 2

Yeah Jim I've seen that. Kinda funny to read a showline breeder talking about the possibility of the sable color becoming a "museum piece". Apparently they haven't seen the BSP as of late. :D

"If your sable dog has black toes, tarheels - he either carries bicolor or black.  If no black toes/heels - he does not carry bicolor or black - no black on toes means he is either sable/sable or sable/blacktan."
 

I have to respectfully disagree, I've noticed numerous cases where that is simply not true.  And also, that there are no logical rules that could support the theory that the bicolor allele is not located on the agouti locus, either. There were originally others that supposed that the bicoloration was not controlled from the agouti locus, but I've found no examples that could support that belief.  Even Willis made the mistake of originally reporting (1976) that the dominant black was present in the german shepherd breed, which he corrected in his later work (1991).  So, even the experts can get it wrong from time to time.

I have known many many many sable dogs for breeding, and have known NONE that had black toes, that didn't carry either black or bicolor.  Not both.  If they had black on their toes, they EITHER produced black, or bicolor puppies.  If no black on toes, then no black or bicolor recessive - they either produced sable, or black/tan as the recessive.  What examples do you  know that dispute this?

molly

another good spot for info on color

http://www.ehretgsd.com/genetics.htm

thanks again darly, great info.

john

Examples are all over, if you look.  And I've plenty of first hand proof as well.  I had a black sable stud (from a sable dam, black sire) who could produce black puppies of course, but when he threw non-sable puppies, many of them did not have toe penciling at all, despite their black recessive.

Look at the numerous progeny of Troll (bicolor), that have no tarheels or toe penciling.  They've gotta have bicolor or black recessives, right?  And if the bicolor locus is separate from agouti, what is the bicolor supposed to be overriding that is actually on the agouti locus?  How about Eick von der Berger Hochburg, who has a recessive black (must, since he has black offspring), but no tarheels or toe penciling.  They're all over.  Only thing is, if I made an exhaustive list, I'd be bound to eventually tell you a few don't, when in fact that actually do, because sometimes it isn't easily discernable from photographs provided.

There are sable dogs that have the tarheels arm bars and toe penciling, and clearly do not have a black recessive.  And they might throw a lot of bicolors.  And you might think I'm agreeing with your theory because you said "or bicolor", but I'm not.  Because if they are unable to throw blacks (i.e., Tom zPS), then that only supports the position that the bicolor allele is located on the agouti locus and not elsewhere, knowing that the bicolor couldn't be overriding the sable pattern.

Have you ever wondered why toe penciling and arm bars are expressed more prominantly on some dogs than others?  Because that is a phenotype that while may be influenced by what's at the agouti locus, the agouti locus alone does not completely control those feature's expression.  What may commonly be found to be true, just isn't always true in this particular circumstance.  Like how recessive black or bicolor accompanied with a black & tan "tends to" (but not always) produce a blanket back phenotype.