Coat determined by 3 genes. New study.

[KingstonTodd]

Coat Variation in the Domestic Dog Is Governed by Variants in Three Genes.
Edouard Cadieu,1 Mark W. Neff,2 Pascale Quignon,1 Kari Walsh,2 Kevin Chase,3 Heidi G. Parker,1 Bridgett M. VonHoldt,4 Alison Rhue,2 Adam Boyko,5 Alexandra Byers,1 Aaron Wong,2 Dana S. Mosher,1 Abdel G. Elkahloun,1 Tyrone C. Spady,1 Catherine André,6 K. Gordon Lark,3 Michelle Cargill,7,* Carlos D. Bustamante,5 Robert K. Wayne,4 Elaine A. Ostrander1,

Abstract:
Coat color and type are essential characteristics of domestic dog breeds. Although the genetic basis of coat color has been well characterized, relatively little is known about the genes influencing coat growth pattern, length, and curl. We performed genome-wide association studies of more than 1000 dogs from 80 domestic breeds to identify genes associated with canine fur phenotypes. Taking advantage of both inter- and intrabreed variability, we identified distinct mutations in three genes, RSPO2, FGF5, and KRT71 (encoding R-spondin–2, fibroblast growth factor–5, and keratin-71, respectively), that together account for most coat phenotypes in purebred dogs in the United States. Thus, an array of varied and seemingly complex phenotypes can be reduced to the combinatorial effects of only a few genes.

The interesting snipit from the discussion:
Notably, these three mutations in various combinations explain the observed pelage phenotype of 95% of dogs sampled, which include 108 of the ~160 American Kennel Club (AKC)–recognized breeds. A total of 622 dogs representing all identifiable coat phenotypes were genotyped at all three loci. By analyzing each of the three major traits both within and across multiple breeds, we show that combinations of these genotypes give rise to at least seven different coat types, encompassing most coat variation in modern domestic dogs. Specifically, short-haired breeds display the ancestral state in all three genes. Wire-haired breeds, all of which have furnishings, carry the RSPO2 insertion. Dogs that carry both the RSPO2 and KRT71 mutations display "curly-wire" hair that is similar in texture to wire-hair but longer and curled or kinked rather than straight. Long-haired breeds carry the variant form of FGF5. Dogs carrying the FGF5 mutation, along with the RSPO2 insertion, have furnishings and long soft coats, rather than wiry ones. When dogs carry variants in both FGF5 and KRT71, the pelage is long and curly. Not surprisingly, coats must be of sufficient length to curl, and all curly haired dogs in our study were homozygous for the FGF5 mutation. Finally, if all three mutations are present, the phenotype is long and curly with furnishings.

None of the mutations we observed were found in three gray wolves or the short-haired dogs, indicating that short-haired dogs carry the ancestral alleles. Our finding of identical haplotypes surrounding the variants in all dogs displaying the same coat type suggests that a single mutation occurred for each trait and was transferred multiple times to different breeds through hybridization. Because most breeds likely originated within the past 200 years, our results demonstrate how a remarkable diversity of phenotypes can quickly be generated from simple genetic underpinnings. Consequently, in domesticated species, the appearance of phenotypic complexity can be created through combinations of genes of major effect, providing a pathway for rapid evolution that is unparalleled in natural systems. We propose that in the wake of artificial selection, other complex phenotypes in the domestic dog will have similar tractable architectures that will provide a window through which we can view the evolution of mammalian form and function.

Time for a reliable company to make a test for these 3 genes and it will tell us everything we need to know about our dogs coat.

[Lucky Me]

Lost the link on my crashed computer, but...
there is even a gene with the doodles for a clear(non-hairy) face & a hairy face!

[Jac]

Wow! Great information Todd! Thanks! Judi, hope you can recover some of your lost research!

[KingstonTodd]

As an early generation breeder wouldn't it be nice to know if one of our puppies "carry variants in both FGF5 and KRT71, the [coat] is long and curly. Or especially to know which ones were carriers of these genes to know which pup to keep back for breeding.

[Jac]

Originally Posted by KingstonTodd

As an early generation breeder wouldn't it be nice to know if one of our puppies "carry variants in both FGF5 and KRT71, the [coat] is long and curly. Or especially to know which ones were carriers of these genes to know which pup to keep back for breeding.

Incredibly important!

[KingstonTodd]

This table and picture reallt help understand the three genes and what we could know if they develop a test for each.

[MaxandMe]

THANKS TODD ........you might be interested in one of the books i got .......Little's book of genetics as it's like the bible of early genetics
but it costs a bit even used. I will give the exact title and more info later today.

OH in the book while it doesn't depict a chart like the one
you have (totally great i might add) it does have the same info.
(this book is quite scientific .....think it might be up your ally or for anyone like us that LIKE GENETICS!!)

NOW to identify the exact genes that exciting but it will be some time BEFORE genetic/dna testing companies i think will have
a test that can do this. in fact the gene for what we call GUN DOG or TOLLER RED .....one of the more prominent companies
still has yet to have a test for this as many breeders were interested as many reds fade BUT a true RED goes 3 genes past regualar ones
that determines TRUE RED that deepens with the dog's maturity.

While they show us in genetics why things happen, companies having the tests to show this take a long time or
have to have enough requests otherwise it stays in the hands of scientists/genetic research.

[Jac]

Actually, AM, I believe that they DO test for coat length now. I have considered it...

But I don't know if the testing is related to this study for the 3 different genes...Wish I had more time to review this stuff!

[KingstonTodd]

If you post a link for the company and the test for length I'll look into if it is this specific mutation the paper talks about. I imagine it is, and it would be so usefull in evaluating F1/F1bs as future breeders, eh Jac?

The part I find interesting is the "furnishings" to which I understand to include face hair. Some Early generation doodles have lots of face fur and and some don't. Clearly from the retriever the doodles are getting -/- for RSPO2, no furnishings. I wonder if poodles are +/+ or some are +/-, since they shave their faces anyway you would not really notice a poodle with less face furnishings in that scenerio (and maye why they shave in teh first place?). There are a few consequences to knowing this:

If poodles are +/+ then all F1's are +/- and being heterozygous leads to the variability in doodle face furnishings and there is not much we can do about this.

If some poodles are +/- then some F1s could then be -/-, and they have a retirever face. Hershey is like this, very little face hair. It would be interesting to know if she is -/- or +/-. It would then be possible to start a line of doodles with a poodle that was +/+ to have more/consistent face furnishings in the F1 generation.

[Jac]

Here is one link, Todd. http://www.vetdnacenter.com/canine-long-hair-test.html

I love the discussion...I have often wondered about the muzzle that is not furry...didn't know it was called "furnishing". I have had a puppy or two with less coat on their muzzle, but not actually short coat...interesting.

[MaxandMe]

I too didnt know it was called furnishings.........JAC what companies are testing coat length now? i wasn't aware they did
NOW are you considering this for NAR's and f1b's to see the chance of less labby looking ones and lower shedding possibilities?

and Little's book discusses this quite well and back then told of the studies etc
part of the reason Goldendoodles tend to be more fleece, shaggy/wavy, more often than not a lower shedding to almost f1b or nonshedding

Peanut however is double coated like golden retriever thus in spring she loses major undercoat

[LucyWhitePaw]

Originally Posted by Lucky Me

there is even a gene with the doodles for a clear(non-hairy) face & a hairy face!

If they have a hairy face as a puppy, is it likely they will so as an adult too??

[Jac]

Originally Posted by LucyWhitePaw

If they have a hairy face as a puppy, is it likely they will so as an adult too??

Yes. Sometimes a non-hairy face puppy can grow facial hair, but I don't think it happens in reverse much.

[LabyLabradoodle]

Thanks for the info! I studied that at biology class and I can relate to what you are saying.