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Originally Posted by Suncera  it also makes me wonder How far and long has this gene been carried because the lady I bought my Sasha from 3 years ago. Her male is AKC registered and her Female was CKC registered which back then I didn't understand what I understand now about being AKC and CKC, which that is a whole different political topic and view point. I do know from his pedigree that he comes from a nice line of breeders, so this means this gene is still spreading. And with Sasha's Dam, she has a nice pedigree as well. Like i say I can only speak for Sasha but she did have siblings and her mom and dad was breed one more time before getting the male fixed. I still keep up with Sasha's parents owner as well. |
I am really sorry to have to tell you this, but the gene will carry unknown until it is discovered, and beyond if breeding is allowed to continue after it is discovered, which is why, now that it
has been discovered in both Sasha and the stud, neither should be bred again. It is a situation that could 'spider' out like broken glass or ice on a pond...and may already have. If Sasha and the stud were the only carriers in their respective litters, then only their previous breedings together and with other dams/sires would be suspect...but there is likely no way to know for certain if that is the case.
Obviously,
the attached is not something you would ever want to do in Yorkies, but the first chart represents the genetic odds of what would happen were a carrier to be mated with a blue born. As the chart shows, especially in litters of 1 or 2, even
KNOWING a blue born was deliberately being bred to a carrier or if it was being bred to an unknown carrier, the breeding
might still not throw an actual blue born pup, but would most definitely throw carriers because every pup gets 1 gene from each parent.
The second chart shows that breeding a dominant (no recessives for this gene) to a blue born would produce pups that are all carriers of the gene.
Sasha's blue born pup is proof positive that both Sasha and the sire are carriers as blue born occurs with 2 recessive genes since delivery of a blue born pup is 100% accurate. Since Sasha
is a carrier, either her dam or her sire or both are also carriers...and so on
up the lines they come from. Since Sasha has siblings, any of them could be carriers but there may be no way to know for certain unless one produces a blue born...in which case the situation is the same as with Sasha and the sire of this litter...both would be proved positively carriers.
Since Sasha's dam and sire were bred together one more time before the sire was altered, there will possibly also be carriers from that litter. If the dam is still in a breeding program, if she is a carrier, she could still be passing the recessive gene along.