the Panda Shepherd: an observation in Genetics - Page 4

lol, thanks Yvette - you can't really talk about Genetics if you dont have sources.  Schmutz has some fascinaing stuff out...so far she is th only one I know of mapping the color genetics in the Dog :)

If you can get ahold of them these are also some good reads : .

A. Ruvinski and J. Sampson the Genetics of the Dog  (The section on color is written by Sponenburg and Rothschild)
Willis, Malcom B. The German Shepherd Dog : A Genetic History

And if you want to get into the awsome old nitty gritty, Little and Whitney kind of pioneered dog color genetics - you can kind of see where it all started - those are in the J.Heredity...and there is also some good stuff in the Mammalian Genome.

Schmutz's stuff is the most recent though I believe.

Color Genetics are awsome :)

~Cate

Sire to Frankie is

Brain Vom Wolper Lowen, SchH III

www.pedigreedatabase.com/gsd/pedigree/279451.html

Thanks Darylehret for that fabulous example of Blaze variations in Genetcally identical Clones!

jc Ceph, and Uber Land Thanks so much for adding to my understanding of genetics.

TIG, another reason it is quite possible to be a spontanueos mutation, is that it is breeding or being passed like a dominant trait. In Frankie's litter there were other pups, all solid. and when Frankie was bred to other Pure bred GSDs, she passed on her markings to approximately 50% of her get. The rule has applied down the line as well.

1. Backward testing is not needed as long as the "researchers" can show that Frankie indeed has iherited one set of genes from the mother,another from the sire, and that indeed the gene responsable for the spoting was inherited by the sire and also mutated ( differnt from the sire's) to cause the white markings.

2. Yes, all dogs carry the same number of genes and the rules apply to all. It is why they are all lumped together as one species and why they can be interbred to produce fertile progeny who will be " Dogs".

3. This gene may have existed before and been bred out, it may exist today in the gsd in some GSDs owned by people who don't talk about it or go online, and who have GSDs unrelated to Frankie. I understand it is a gene for spotting, I am not sure if it is a "white" gene, but you CAN have it both ways, it could have existed before and at the same time re-ocurred in a sprontaneous mutation to be expressed in Frankie, and later inherited and express in about half of her offspring. (You can be right BOTH ways) :-)

While this spontaneous mutation is so obviuos many others occur but go un-noticed, because they cause less visible change in the individual dog. Many cause little to no change, and more lethal ones will never develope into viable embrios, die before birth, or shortly after.

White, blue, and liver can hide because they are ressesive to their opposite Colored, Black, and Black. this spotting in Frankie looks to be not ressesive.

I could be possible, ( like with Sabino horses) but the way the gene is behaving so far says it is not ressevive the way liver, white and blue are.

Even a dominant trait can be concealed in the phenotype because of genes on another loci overiding it's expression.

Good point Darylehret, I think that is why jc was pointing out the white gene posibly hiding panda features, but yes, that is very possible.

That is very possible - but at the same time neither of the parents where white, right? O.o

lol - I find this all very fascinating, because we could be on the verge of discovering another Locus or two that hadnt been previously mentioned :)

~Cate

Schbabe  " appreciate you sharing the "original data source" instead of just your opinions: Just for your info I've been around long enough that I've had and read Little and Whitney and BOTH Willis books back when they were still new resources.  I also communicated directly by email on this subject with some of the "resources" that Ceph cited rather than JUST reading books. I can not and will not speak for them - that is their business.

Ceph, Thank you for the information you have posted. I am not trying to say you are wrong. I am simply trying to say I think a very "unscientific" and certainly not a rigourous approach was taken on this issue. I'm also trying to say - because of this keep an open mind. I am not a ludite that does not see the value in DNA research but a. its a new science and b. as someone pointed out most of this had been figured out years ago by empirical observation  - a quality I often sadly say find lacking in the academic world. If DNA and geneticists had all the answers  guide dog schools ( who have been using geneticists for decades) would not have such an abysmal success rate. You know sometimes you have to look up from the book  and look at what's sitting in front of you and what it is telling you.  Breeding is as much an art as it is a science.

The reality is while we have a large body of information on color genetics in a variety of species we still do not know the full answer. Even the fox research done on taming and the melatonin pathways has some huge holes in it and may or may not be applicable to dogs. IF it is it suggests there is far more fluidity in the system than anyone has thought. Plus just look at the whole bicolor thing. We can not even effectively define bicolor in our breed because what I think is one you may not. If we can't even agree on what it looks like we are just throwing darts on the wall when we talk about its genetic inheritance.

a quote from you "Why do you think it is the Canine Genome project and not the GSD Genome project....because at the level of the Genotype, each canine has all the same things." well - not necessarily depending on what other "spontaneous mutations' developed over the centuries. What DNA is teaching us is that very very  small differences in the genome can result in major differences in trait and large system expression. At some point the differences accumulate to a large enough point that a new species or subspecies is created.  ( perhaps 2-4% which seems to be the benchmark for differences in the genome between mammalian species human/dog  human/chimp etc)

Again just food for thought - if everyone is the same - why do cat clones show up with completely different markings than the original?  The GSD does not have the lethal white gene tho many mammalian species do. The white in GSD is not associated with blindness or deafness AS IT IS in many dog breeds.  Our blues do not have the skin issues of an Isabella Doberman. Our black is NOT dominant AS IT IS in many dog breeds. The suppossd end all and be all of the dog genetic DNA "tree " ( which companies of course are making money on) places the GSD with Mastiffs and NOT related to Belgians and Dutchies and other herding breeds.  Please - give me a break.  Just saying that for me there is still plenty of room for healthy skepticism and reasons for looking at other places that Frankie may have come from and that science is not yet the god some are willing to proclaim it.

I have nothing to add to the conversation but want to offer a Thank you for some fasinating, intelligent reading. jh

When you interbreed any population enough, you're going to get alot of homogenous combinations that would just not be mathematically/statistically possible in the genetic diversity of it's wilder progenitors, especially given that the expression of theirinheritance is often a combination of polygenic, incompletely dominant, and multifactoral in nature.

That's why over 400 breeds look distictly today very different from a wolf, and each has their own bottleneck for different potential "lurker-genes" that may eventually one day be surfaced, even after 50 generations of leaving no trace of their presence.  That's why each breed has health concerns for conditions that other  breeds may not be concerned for.

That's the beauty of evolution.  There's far more unexpressed data in the blueprint, than could ever be "turned on" for expression in the phenotype.  You'll probably never see wolves suddenly grow floppy ears, webbed toes, merle color patterns, or bushy curled tails, but it's available in their DNA.

As far as the bicolor thing goes, I'd rather categorize it by genotype, than by phenotype.  What I mean is, by what it reproduces in its offspring, rather than someone's subjective opinion of it.  For example, not everyone agrees with my definition of the term: "Black sable" - a dog that is sable, with a recessive black gene. This could be a dog with or without black armbars and toe penciling. Those markings may often be present on a dog that has a recessive black gene, but there are exceptions. I prefer to think of the black sable as what the dog produces genetically, and not necessarily by it's appearance. So, a very dark sable that doesn't have the black recessive, I call a "dark sable". But, dark sables often are black sables, though there are exceptions.

So why are they saying it's coming from the sire and nothing from the dam?  I thought both had to contribute for such genes?  Can some explain why they say the bitch's genes had nothing to do with it?  Maybe I am not fulling understanding all the above statements in the thread and on the Panda Shepherd website. 

Karmen