Most of the information here has been taken from the Book,
Genetics of the Dog by Elaine A. Ostrander.
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 picture is of a poodle, with face shaved, naturally would have long hair on face)
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
Feel free to contact me (Ashton @ firstname.lastname@example.org) if you have any questions about anything on this page or if you have anything you feel needs to be corrected. I am always willing to help another breeder and am always wanting to learn more as we discover new things in the world of breeding and genetics!