genetics- strange litter colorwise........ - Page 3

""dominant black" would not explain a sable pup from two parents that were not sable (at least one of them)."


Yep, dominant black can 'carry' sable unseen.  The black parent carrying wild type on the K locus, mated to another K locus wild type (tanpoint), allows the A locus (sable in this case) pattern to show in the offspring.

Molly, the explanation you give for the sable from non sable parents is perfectly feasible. That, notwithstanding, does not negate other explanations for the sable offspring in this instance.

There is no reason why dominant black x tanpoint should not produce sable. It can be explained very simply without having to give actual examples. Hope this helps -

Black parent - a^w_ K k^y

black & tan parent - a ^t_  k^y k^y 

Sable offspring - a^w a^t   k^y k^y


If there is a rule about sable always having a sable parent, then it needs updating.  Other colour combinations that can produce sable are -  white (recessive yellow) x any GSD colour except white.  Recessive yellow can disguise just about any other pattern by stripping out all eumelanin pigment, so a genetically sable dog becomes white, or actually pale cream.

And if we go into other breeds, red sable (which is true sable... GSD sable is in fact wolf sable) can also carry 'sable' unseen and so produce it to many other colours.  Also brindle can produce sable to other colours.  There are others... merle....

ok, but actual examples please?  Are there any?  If not, then this would be theory only - an interesting theory for sure, but theory only, not fact - as in, there are no sable puppies produced from two non-sable parents, one of which proven to be dominant black. 

I get the white, and know this is possible - I'm sure there are examples of white producing sable with a non-sable other parent - but this is white masking the sable - something that is known to be possible, with actual examples.  I don't follow white genetics so wouldn't be able to find those actual examples though.

molly

Molly, it's not possible to give examples in the GSD breed as there is no definite evidence so far that dominant black occurs in the breed.  There is increasing evidence for its presence, but these anomolies can be explained in other ways.

I've no doubt that there are examples in other breeds, I'm sure you would find them if you looked.  Breeds that have the necessary genotype - German Spitz, Pomerainian, Finnish Lapphund.... and probably many more.  There is no reason why dominant black mated to black & tan could not produce sable (wolf sable) if the necessary alleles were present.

I have never ever experienced a black dominant GSD,neither has any of lots of GSD breeders that I know.I have recently read an article that GSDs and one other breed / I do not remember which/ are the breed where black is ONLY recessive.
With that sable pup from non-sable parents it can be as Molly stated - they misinterpreted the color or the official sire of the pup is not its real biological sire - DNA tests are not 100 percent reliable.

pod - ok it's good to keep that in mind then - it does make sense as you explain it as a masking gene like the white - but until/unless there are actual examples of proven dominant black siring sable puppies with a non-sable other parent - then it must be considered theory, not proven fact. 

Until then, the fact is that a sable pup cannot be produced from two non-sable parents.  That's been proven as fact over and over again.  I'm game for opening up to other possibilities, but in the grand scheme of things it pays to be cautious about what is considered fact and what may be possible, but isn't proven to be fact.

I had "heard tell" of dominant black dogs (German Shepherd dogs of course - other breeds do not compute into the GSD color gene discussion) - but so far have never seen one or even seen a pedigree of one.  So, for me they exist only in theory.  I would love to see the evidence that they exist - would be a good thing to have knowlege of.  Factual knowlege.

molly

Other breeds do matter very much Molly!  The same genes are present in other breeds and dominant black most certainly does explain a sable pup from two non sable parents.

It would be very difficult to prove the existence of dominant black in the GSD without DNA testing, hence my plea for someone with a suitable dominant black candidate to approach HealthGene to have the necessary analysis done.

 A sable pup CAN be the product of two black and tan parents (or any other combination of colors) IF both parents not being sable themselves carry a sable recessive gene. It's called a double recessive.