There are three genes that affect coat type, giving seven different coat combinations. These seven combinations include: short hair, long hair, curly hair, wiry hair, curly wire hair, long hair with furnishings and curly hair with furnishings. The three genes responsible for coat type are the RSPO2 gene (furnishings), FGF5 gene (long hair) and the KRT71 gene (curly gene). Both the furnishings gene and the curly gene are dominant and only require one copy to give you a curly coat or a coat with furnishings. But, the long hair gene is a recessive gene, so you need both copies in order to get long hair. For the purposes of giving a basic understanding, we will use F for the furnishings gene, L for the long hair gene and C for the curly hair gene. If the letter in noted as a capital is in Dominant and if it is a lowercase letter it is recessive.
FF or Ff - the dog will have furnishings
ff - no furnishings
LL or Ll - short hair
ll - long hair
CC or Cc - curly hair
cc - straight hair
_ - means it can have either the dominant or recessive form
Here are the looks that you are going to get when combining these genes:
1. ffccL_ - is a dog that has short hair, no furnishings and straight hair - ex. Labrador Retrievers, Beagles.
2. F_ccL_ - is a dog with furnishings, but no curl and short hair - Australian Terrier
3. ffccll - is a long haired dog, with no furnishings and no curl - Golden Retriever
4. F_C_L_ - is a curly haired dog with furnishings, but short hair - Airedale Terrier
5. ffC_ll - is a long and curly haired dog with no furnishings - Irish Water Spaniel
6. F_ccll - is a long, straight haired dog with furnishings - Bearded Collie
7. F_C_ll - is a long, curly haired dog with furnishings - Poodle, Bichon Frise.
Note: These are only the genes that they know of, there is lots of variation within these genes, especially the curl gene and there are probably other gene modifiers that account for the variation and other coat types that are seen.
How does this relate to Goldendoodle Breeders?
If we are wanting to keep the traditional Goldendoodle coat we need to keep these genes in mind and once breeding past the F1b generation, we need to test for the Furnishings (often referred to Improper Coat or IC) and for the Curl gene. We do not need to test for the long hair gene as it is a recessive gene in which both Golden Retrievers and Poodles carry two copies, so their offspring will automatically carry two copies as well. What we want to make sure is that one parent in every breeding pair carries two copies of the furnishings gene and one parent carries two copies of the curl gene. We will show examples of breeding pairs and what the outcome will be:
A Golden Retriever is ffccll
A Poodle is FFCCll
An F1 Goldendoodle is FfCcll
An F1b Goldendoodle can be FfCcll, FFCcll, FfCCll or FFCCll (because of these four different variations, you can get lots of variation fro here on out)
Here are a few examples of an F2b generation breeding and the different outcomes:
F1 bred to an F1b that carries one furnishing gene, fbut does carry two curl genes:
FfCcll bred to a FfCCll
75% Proper Coat
25% Flat Coat, with more curl than a Golden.
F1 bred to an F1b that carries one furnishing gene and one curl gene.
FfCcll bred to a FfCcll
56.25% - Proper Coat
18.75% - Coat like a Bearded Collie
18.75% - Flat Coat, with more curl than a Golden
6.25% - Golden Retriever Coat.
F1 bred to an F1b that carries two furnishings genes and two curl genes
FfCcll bred to a FFCCll
100% - Proper Coats
Furnishings, Curl and Long Hair genes can all be tested for a most labs, but the mains ones we are aware of are Paw Print Genetics, Animal Genetics, Vetgen, Embark, and DDC.
The shedding locus is a relatively new gene out there now too, that can help in aiding us to help achieve the least amount of shedding possible.
For this gene there are two alleles, one that is associated with high shedding and one that is associated with low shedding. Some breeds have two high shedding alleles and some breeds have two low shedding alleles. In some cases we can assume Golden Retrievers have two high shedding alleles and Poodles have two low shedding alleles but this is not always the case. Unlike furnishings and curl both Golden Retrievers and Poodles can have any combination of high and low shedding genes.
+/+ = two high shedding alleles
-/- = two low shedding alleles
It is believed from research that this gene has interaction with the furnishings gene as well. This is why you should test for both the furnishings locus and the shedding locus. When combining the results of both tests you can identify the level of shedding you should get in the tested dog. So this is what this looks like. Shedding rates can go from 0 to 4, with the least amount of shedding in a dog with a 0 rating and the highest amount of shedding in a dog with a 4 rating.
FF-/- = 0 Shedding
Ff-/- and FF +/- = 1 Shedding
ff-/-, Ff+/- and FF +/+ = 2 Shedding
ff +/- and Ff+/+ = 3 Shedding
ff+/+ = 4 Shedding
The easiest way to look at this is for every IC (no furnishings) and every + shedding gene you add one point, the more points the more shedding you will get. This gene shows variation within it, so it is more to be used as a comparison to other dogs instead of an exact amount of shedding.
It has been noted that the furnishings gene seems to have a slightly higher effect on shedding than the shedding gene does though, so you will see more shedding in a ff +/- (3) than an Ff +/+(3).
Currently Paw Print Genetics, Vetgen, and Embark all test for this locus. This is very new, but we look forward to seeing the results of testing with this new allele and the differences breeders find with it. We hope it will be a great tool for breeders to use!
Coat Genetics for Breeders