gsd colors - Page 6

We've had previous threads here that suggest dominant black may be present in the breed, possibly from outcrossing to another breed or even a point mutatiuon.  This could explain the appearance of other A locus patterns from black x black breeding.  An unbroken line of solid colours (Black, liver, white) in the pedigree could indicate how far back the mutation or outcross was.

Good point. I do believe that dominant black has re-entered the breed in the Russian conformation lines.

e.g.: http://www.pedigreedatabase.com/german_shepherd_dog/dog.html?id=522436

The recent thread I was referring to, though, is from two Dutch KNPV working-line GSDs, and the mom does have bleedthrough on her legs.

The Russian dogs (dominant black) have no bleedthrough.

Christine

Do you have some way of confirming that this dog that you linked is indeed dominantly black?

Did you look at his parents, siblings, children, children's children, previous breedings of females bred to him, etc.? If you click around a bit, you see that it's really the only reasonable possibility. Also note the unbroken line of black parents and progeny.

I exchanged e mails previously with the Russian breeder and they confirmed to me that their black color is dominant (without further explanation from them) but did not explain how they reached to this, it is confirmed it's dominant. I though think it is dominant to b/t but not sable.

Ibrahim

I don't see a dominant black pattern, that's why I ask. Looks recessive to me.

Dominant black is at the K locos, suppressing expression of sable (at least in wolves).

Dominant black is K locus yes.  It overrides or suppresses - sable, wolf sable, tanpoint and recessive black.  To be precise, dominant black is dominant over K^y the allele most common in the GSD, that allows A locus patterns to express.  What might be a bit confusing though, is that it is a pattern (as is A locus) not a colour, so other recessive colours like brown (liver) or blue can express on it.  

Another colour (actually another pattern) common in the GSD than can actually override (the correct term here is epistatic) it is recessive white/cream.  A white GSD could be genetically dominant black and produce black puppies bred to any other coloured dog.

Pod,

Just to make sure I understood you correct, is it possible that this dominant black GSD in Russia got this dominance due to introduction of a white shepherd back in its pedigree?

One more question (thoretically) what colors of puppies is the possible outcome  of breeding a white GSD to a solid black GSD (the ordinary solid black we know of)?

Ibrahim

More likely that the Russian breeder is confused. I still see no evidence that bicolor, blanket back, and black and tan are not determined from the same locus. If it were a separate modifier involved, then I believe it would have to be closely linked (inseparable) with A locus, in order for a more dominant pattern of the A locus (saddle back) to not arise from a lesser dominant pattern (bicolor). That is, assuming that you do not want to differentiate between the allele types as as/at. Meanwhile, ya can't fix what isn't broke. I'd make sure they use a couple bicolor dogs in their next study.

Ibrahim, it is possible that a white shepherd can 'carry' dominant black but the new allele would have to have come from somewhere if not from a new mutation. So the white, or any dominant black GSD would have to have had a cross to another breed in its ancestry to supply the dominant black.  Possibly from a GSD x Groenendael.

The white colour in the GSD is sometimes known as a 'masking gene' within the breed and this is a good description as it can mask almost all other colours.  So yes a white bred to any colour other than white, has the possibility, depending on which other genes are carried, of producing any of the known GSD colours including recessive black.  White to white of course will produce only white as it is a recessive.