the Panda Shepherd: an observation in Genetics - Page 3

Thanks Ceph.

jc,

I really can't find the page now and don't want to spend more time looking, but the reason I and others say it was a spontaneuos mutation ( I Think others as well) is that on that panda website there used to be an explanation that basically said this is what the " Researchers " working on the DNA concluded, and they even found out the mutation was on gene contributed by her sire, so Frankie is not Homogeneous for this Panda trait in genotype. It was not the Panda breeder's theory, but what was told to her. Anyhow the site has changed alot. I remember being able to see Frankie's pedigree somewhere on the site and now I can't find a pedigree for any of the dogs. I think the Panda creater got so blasted and hated for deciding to go forth and create a breed from Frankie's Mutation, that she has shut of from the GSD world. I noticed a note on that site at one time saying she had lost all her friends in the GSD breed because of her decision, etc, and how her mind was made up, That she was going foward with the Panda program. ( I don't see that anymore, but I saw it years ago).

Still, if you had a line of " White GSDs" they could carry the panda trait under the white and you would never know, but Frankie came from pigmented Solid Colored dogs.

I image, that even if the "Mutation" occured on a gene contribued by the sire, if it was Spontanues, then it means he is not a carrier, but that a " Freak Spontaneous mutation occured " on that gene he contributed, but I don't know when they happen, durring gamete formation in the male? or durring developement of the embrio?

On an interesting note, I have heard that the size of white markings on many colored mammals has to do with how soon the white or unpigmented cells form durring embrionic developement, and it has been observed in Cloned White and Black calves, that they develope similar but still very unique coat patterns despite being identical sibblings, and therefore genetically identical.

What does make me sad thopugh is how the Panda breeder was treated, because it would seem to me that being that nasty to a person because of the color of the dog they chose to breed from is even worse than breeding for color in dogs.

>they develope similar but still very unique coat patterns despite being identical sibblings, and therefore genetically identical.

That is fascinating!

That's awsome...Genetics are awsome...t6he combinations are endless and I LOVE it :)  It's like one big messy equation :p

~Cate

Blaze patterns of the first five Smart Little Lena clones

NARRATOR: So how can dogs be so different and yet remain genetically so much the same? Mike Levine thinks the key may lie in stretches of DNA that, until recently, were dismissed as meaningless.

Only part of the DNA in every cell actually codes for proteins, the building blocks of life. The rest is a mystery. Some stretches probably are meaningless. But many geneticists now believe that buried in these mysterious stretches of DNA are critical instructions for turning genes on and off.

MIKE LEVINE: Turns out that there are two parts to the gene. There's the famous part, which encodes proteins. Then there's the less-appreciated part, where I think the real action is, and this is in the so-called "regulatory" DNA. It tells the protein coding part of the gene where and when to be active. It is the software of the genome.

NARRATOR: According to Levine, subtle changes in this software could produce remarkable diversity and do it without changing the DNA that makes a dog a dog. All these dogs could have the same genes for leg growth, the only difference may be in when those genes are turned on and off. The frustration for geneticists like Mike Levine is that, so far, they haven't been able to crack the code of the regulatory DNA.

http://www.pbs.org/wgbh/nova/transcripts/3103_dogs.html

I have some problems w/ the flat out statements that are being made by the Panda people and Davis. At the time of the original testing Davis had no clue that in fact historically there had been "piebald" GSDS ( mentioned in the old standards but no one knew what they looked like - some suspected it might have meant merle).  So first and foremost if you don't know the breed history how can you KNOW that this is a spontaneous mutation and NOT a lurking gene( as we have seen before other off colors can lurk for many many generations before resurfacing again).  That alone to me raises a HUGE question about the whole "scientific" validity of what is being claimed.

Secondly the testing that was done( based on emails exhanged w/ Frankie's owners right after it was done) basically JUST established that Dad was Dad and Mom was Mom. Once again "scientifically" this proves nothing. It certainly does not prove the purebred status of either Mom or Dad.  For all we know there could have been a cross breeding(accidently or on purpose) a generation or two back. If the dogs chosen to go forward phenotypically looked like GSD there would be no way to know but they could have been carrying the tricolor genes and since the testing did not go back up the pedigree (which in my opinion it should have) we will never know.  Again I have to condemn the lack of good research and  "scientific" approach on the part of the researchers who did the testing. What were they thinking that they did not apply a far more rigorous standard to their investigations.

I have discussed this with several very well respected and knowledgeable GSD people including professional geneticists and that is the suspicion of several for two reasons. One the color pattern too closely resembles some other breeds and there is an uncharacteristic head structure on many of the progeny - at first you want to say a coarseness but it is not so much a coarseness as a wrongness to the structure that draws the eye.

I have no way of kowing whether Frankie's owners are raking in the bucks but I do find it interesting the speed w/ which they set about establishing a "separate" "rare" breed especially after their initial protestations that they had no intentions of doing any such thing. The biggest problem w/ all of this that I see is that when you start to breed for 1 and only 1 trait to the exclusion of all else you have just made a genetic black hole for yourself and your dogs and unfortunately sooner or later their owners.

The only thing is - you are generally going to know if a dog is a carrier for one of the recessive alleles at the spotting locus because all the alleles are incompletley dominant.  This means that even though the dog is a carrier for the dominant allele, in this case S, if they carry for, lets say, Si then they are going to express that recessive allele in their phenotype a little bit.  This is one of the few Loci where you can kind of guess at the genotype based of the phenotype, even as a recessive carrier.

The small white spots you see on chests - probably the expression of a recessive spotting allele.

As far as those at UC Davis - I cant say that I know either way - but I can see where they think it is a mutation.  For Franka to end up with that much white in that general pattern she is probably si-sw or sp-sw...I would guess at the former though.  That means one parent carried for si - which would express itself in a small bit of white on the parent, and the other would carry for sw - which would express with a fair amount of white on that parent.  Correct me if I am wrong - but both parents were dark and didnt appear to have any white markings, correct?  That would lead me to thinking that it was a random mutation...

I need to start using generation #s...grandparents are f1, parents are f2, Franka is f3.

Even is f1 was another breed - say a collie, which is generally a carrier for a recessive allele at the spotting locus, if they passed that allele on to f2, Franka's parent, that allele would express itself.  As far as I know, there are no other known loci that cause spotting other than those at the spotting locus...and maybe this mutation.  There is no recessive trait in another breed that could have hidden and caused this, and whats more...if the mutation was caused by another breed being brought in at f1, then the f2 would express that dominant trait - which means if it was a mutation it HAD to occur on Franka.

lol - I cant tell if I am making any sense...but I hope that explains some.

~Cate

Cate, Don't have time tonight to go back an re read all the genetic info but need to make three points. 1. Because there was no backwards testing there is no way to know that this is a "spontaneous" mutation. We would have to know the sires' parents DNA structure to see if they carried the "mutation" * or gene by any other name. ONLY if they did NOT would you know accurately and truthfully if this was a "mutation" vs a lurking gene. This was NOT done so all is left to speculation. 2. There are well known differences in GSD color genetics from other breeds so you CANNOT presume how it works in breed a,b or c is how it works in the GSD. 3. Because the backward testing was not done the issue is and always will be unresolved if this was/is a color pattern ( it may be far more complex than a white allele)  that existed in the GSD (see old standard references). If white, blue and liver can "hide" for 6,7,8 generations ( wh/ I have personally seen) and then reappear because the right individuals happened to be bred together why could not the same happen here.

In respsonse -

1. I just pointed out if it was the latent spotting recessive alleles you would know - because that locus is incompletley dominant then the recessive genes WOULD in fact present themselves in the parents.

2. The GSD still has ALL the same Loci that every other dog has.  The difference isnt in the Loci, it's in the coding of the Loci.  Thats why Geneteicists can write books called The Genetics of the Dog.   Each dog has all the same Loci - whether it be the Spotting Locus, the Merle Locus, the Ticking Locus, the Extension Locus or the Random Unknown Locus.  However, each dog is coded differently at these Loci which is what makes each breed different.  So yes - generally you CAN presume thats how it works with a,b and c because they are all Canines and the loci are all the same and the alleles carried at each Loci are all the same....the coding of the alleles however is different.

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.

3. I did say that it is quite possible it is far more than that - I dont know, I am not a geneticist.  I am just trying to make sense of it based of research I did from known Genetecists such as Sponenburg, Rothschild, Schmutz, Little, Whitney and Willis.  Those are my refrences and they are the ones that started the ball rolling on canine Genetics all the way to Mapping it.

But here's some more comming knowledge for you....the Dilutione Locus, the Extension Locus and the Brown Locus (thats the Loci affecting Blues (coded D for Normal, d for dilute blue), Whites (Em for mask, E for pattern but no mask, and e for masking white),  and Livers (B for Black and b for liver) are NOT incompletley dominant.  The Spotting Locus is.  A Em-e dog isnt going to be kinda white, they're going to have their Agouti Pattern with a Mask, a B-b dog isnt going to be kinda blue, they're going to have full color - in these cases the dominant genes are that - completley DOMINANT.  However, at the Spotting Locus if you get a dog coded S-Sw, thats dogs gonna have a white pattern because that dominant S allele cant completley cover up that recessive allele.

The Spotting Locus is a completley different monster.

~Cate

~Cate,

Thanks for posting the link to the website on canine color genetics.  It looks like a fascinating, albeit tedious, read.  I'll pour some more Java in my mug and read through the content.

I appreciate you sharing the "original data source" instead of just your opinions.  Kinda refreshing for this board...

(oops did I say that out loud?)

Yvette