the Panda Shepherd: an observation in Genetics - Page 2

Sorry - here's the link - it isnt the J.Heredity article...thats costs money, but it is essentially the same thing she wrote :

http://homepage.usask.ca/~schmutz/white.html

~Cate

Ohh gosh, I love the Art on Shaw's Site, the text is just upseting to read.

This article? I'd always been under the impression, however erroneous, that white was a dominant aspect. Yes I very familiar with lethal white overo, though most people don't know the technical terms. I've had enough first hand experience with it.

White is ressesive in the GSD. White GSD do carry a Patern serries under the white that is not expressed, ( Solid Black, Black/Tan, Bi-Color, and Sable in any of the combinations. ) since the gene causing the white in GSD is on a different Locus than the genes for the pattern. the dog can have only one copy of the white gene, and be solid black, solid sable, B/T etc.

What he said :p

lol - apparently you didnt need to pay for the article...lol, I feel kind of ripped off.  But yeah - thats the one.

But Willis and Little and Sponenburg and Whitney all knew that White was recessive even before it was mapped.  Because if it was dominant then you would be getting colored whites out of white to white breedings, you would get completley white litters out of white to colored dogs (which doesnt happen either...the most you'll get is fifty percent white pups, which is a colored carrier to a white dog) and you wouldnt be getting white puppies out of colored breedings (which you can get up to 25% white pups out of a colored breeding).

White has always been recessive...breeding shows that even without the tests.

~Cate

the comment was made that most of these spotted patterns occur with breeding into the white lines. 

that is not totally true.  the panda started out of 2, very dark(a solid black and a dark blk/tan) mostly german bloodline dogs,  not from a white/color cross breeding.  I have seen quite a few top dogs, on both sides of the ocean produce the irish spotting.  I have seen large white chests, white stockings on the legs, and even the white blaze.  all of these have been either top american showline, or top german showlines.  People in American rings should remember a Clayfield Texaco son named Skunk (a Clihu/Crosstimber joint breeding), so named because he was born with a white stripe up his forehead.  he shows up alot in Clayfield, Clihu and Crosstimber dogs.

you can find pedigree's and DNA results on the ladies website who started the Panda Shepherd.

Oh - and for lethal white - it's really easy to avoid - just dont breed two Frame Overo's together...breeding two together is like breeding two merles...its just a bad idea - especially since there is only one foal - 25% chance of a foal dying before...what is it...72 hours?  Those just arent good chances and can be avoided pretty easily.

My program doesnt have paints...we deal mostly with warmbloods...but we go very deeply into equine genetics...that is my emphasis in my field of study...lol...I know horses a little better than I know dogs.

~Cate

you get the same thing when you breed to merle's together, you can get "lethal white" puppies, some have no eyes, can be blind, deaf, all of the above.  happens in most collie type breeds.

Ceph,

is the lethal white the foals born with no rectum? I heard this is what kills them,they look normal, the intestinal track does not follow though, so they die slowly from this. Also Hear it might be a Linkage issue and pehaps not the same gene. I just want to clear up if the problems from the lethal white in horses are distict from the merl gene in dogs that we are now talking about.

Yes - they have an underdeveloped digestive system which is in the end why they die.

From what I know, Dr. Sponenburg (pretty much wrote the book on equine color genetics) still says it's at the Overo Locus.

Oh - I didnt mean to say they are the same thing - but breeding two overos together isnt a whole lot different than breeding two merles together.  In both cases the homozygous dominant combination is what causes the problem.

~Cate