Frenchie Color Genetics

A quick over view.

French Bulldogs have many colors and color patterns that when mixed together gets you the final color appearance of the dog. Each color and color pattern has its own compartment in the dogs coloring pallet called Locus (meaning Location), each Locus has room for 2 gene variants called Alleles. When these Locus are put together they end up giving you the final coat color of the Dog.  Chocolate, Blue, Black, Cream, Fawn, a variation of Brindle, Tan and Point and so on…. The lettering that you often see when someone’s trying to portray their specific dogs color DNA in letters is the Locus and Allele. You can look at it like this, a Locus and its Alleles for a blue dog looks like this (d/d). The little d’s are each its own Allele and the parenthesis that that hold both Allele together is the Locus. The compartments or Locus are broken down as such: Blue, Chocolate, Cream, Merle, Piebald all have their own locations. Ay(fawn)/At(tan and point)/a(solid black) and AW(sable) share another at the A-Locus. The next locations that shares a location with another Allele is the K-locus (known as the dominant black Locus) and here you have the Ky (allowing gene-more on this later) and the Kbr (brindle) gene.

When you see a big letter and or a little letter in the places where the Alleles are it is telling you if the dog is a carrier or a non-carrier of that specific color trait and a little letter means the dog IS a carrier of that specific color trait. Blue, Chocolate, Cream, AT, a, pied are all recessive genes meaning you need 2 copies to occupy a locus for the color to be expressed in a dogs coat. So blue would be (d/d) and chocolate would be (b/b). If a dogs only carried 1 copy of the blue gene (D/d) the blue color won’t be expressed in the dogs coat. Merle and Brindle are dominate genes meaning you only need one copy of the gene in its specific location of it to be expressed in the dogs coat.

Below is a quick explanation for most of the Locus (locations)  that are in the French Bulldogs coloring panel, that when put together gives your dog its final coat appearance.

 

K-Locus, also called the dominant black locus. Making Fawn and Brindle French bulldogs

If a dog is brindle it is determined at the K Locus(location). Two sets of Genes can be held here at this location, ‘Ky” and “Kbr”.  The “Kbr” gene, also known as the brindle gene, is dominant over the “ky” gene. If a dog carries one copy of brindle it is showed as (kbr/ky) in the K-Locus or two copies(kbr/kbr). If the dog have 1 or 2 copies of the brindle gene the dog will express a brindle coat. The “Ky” gene, its known as the allowing gene. This is because when 2 copies are present it allows the A-Locus, the D-locus and B-locus to determine the dogs coat over all pattern. The “Kbr” brindle gene interferes with the color expression of the A,D and B-locus giving you the brindle look

 

A-Locus. Solid Black, Tri-color, Fawn and sable Locus gene here.

Boy is this Locus crowded! The four genes held at this location are “Ay” for Fawn, “At” the tan and point or Tri-color gene, “a” the solid black gene and “aw” for sable. “Ay” and “Aw” are very similar and are dominant over, “At” and “a”, making it so the tan and point or Tri-color gene “At” and the black gene “a” are not noticeable in the dog. “At” is dominant over “a”, so if a dog is (At/a) at this Locus the dog will show the same markings as a dog that’s (At/At). If a dog is (Ay/At)(Aw/At)(Aw/a) or (Ay/a) the dog will be fawn or sable not showing the traits from the tan and point gene of the solid black gene. A Dog will only be full solid black if its carries two copies of the “a” gene (a/a). A dog who’s brindle (kbr/kbr)( kbr/ky) will be brindle expressing itself over the A location. If a dog is (At/At) or (At/a) the brindling will be expressed where the tan points should be. If a dog is (Ay/At)(Aw/At)(Ay/a) or ( Aw/a) and carries 1 or 2 brindle genes the brindle will be expressed all over the dog. If a dog is (a/a) and carries 1 or 2 brindle gene the brindle is not expressed because since (a/a) is solid black and brindle is black that allows some fawn to come though there is no fawn to let though so the brindle is not noticed.  If the dog is Ky/Ky not carrying a brindle gene it allows all genes in the A location to be expressed with out any interference.

D-Locus. Blue French Bulldogs

The blue Locus seems to be everyone’s favorite. A fun fact about the D-Locus is actually just a dilute gene. It dilutes(waters down) the colors that the dogs are in the K-Locus and A-locus. If a dog is solid black with 2 blue dilutes its becomes a solid blue dog! If the dog is a Fawn dog with 2 blue dilutes it becomes a Blue Fawn, champagne color.

B-Locus. Chocolate French Bulldogs

This Locus work similarly as the D-locus. It is a recessive so 2 copies of the Chocolate Allele is needed for the chocolate color to be expressed. At this stage of color testing in dogs they have yet to develop a test to confirm if dogs carry chocolate or not. The only way to truly confirm if a dog carries it is if you breed it to a dog that is chocolate or carries chocolate and you get some chocolate puppies as an outcome.

There is also a different shade of chocolate that looks totally different then the original chocolate  that has been introduced over the years. They are calling testable chocolate because it can be tested.

E-Locus. Cream French Bulldogs.

This Locus is called the Reverse yellow Locus but we know it as Cream : ) Cream is the most dominant gene is the Frenchie color pool if 2 copies are present in the Locus “e/e”. If a dog carries two copies of cream at the E-locus (e/e) the dog will be completely covered in cream no matter what color or pattern the dog carries. In most cases if a dog carries one copy of the cream gene (E/e) a slightly lighter coat can be noticed on whatever dominant color the dogs coat is. So, for example is a dog is Blue(d/d) and carries one copy of cream so its (d/d E/e) the dog will appear at times a little lighter blue compared to a dog that carries no cream. If a dog carries 2 copies of cream on a blue dog so it’s (d/d)(e/e), the dog will be completely covered in cream

Tri Color French Bulldogs

These are my personal favorite. There are many Tri color variations; Black and Tan, Chocolate and Tan, Blue and Tan, Lilac and Tan and Merle and Tans. What gives these dogs tan point markings is the Allele combination at the A-Locus. The “At” gene is the main component in giving the dog its tri-color appearance. As mentioned before the At gene is dominant over the “a” gene. So if a dog is (At/At) or (At/a) at the A-locus the dog will express its Tan Points. Apart from the dogs tan points what gives your dog its coat color is what Alleles your dogs carry at the D-Locus, B-Locus and M-Locus. The coat of a tri color dog that doesn’t carry 2 alleles of blue or chocolate base color is solid black.

Lilac French Bulldogs

This color is a combination of the D-locus(Blue) and the B-locus(chocolate) when 2 copies of each Allele are present at each Locus (d/d)(b/b). The coat will usually have a purplish color if the dog carries one or 2 copies of the “KBR”gene or be solid purple is the dog also is solid black to Tri color. (a/a)(at/a)(at/at). IF the dog isn’t Tri color, solid black (a/a) or carry the brindle gene the dog will be a lilac Fawn having a more yellowish champagne look towards it apposed to a blue fawn what would look snowier champagne.

M-Locus Merle French bulldogs

The Merle gene is held at the M-Locus. A dog only needs to carry one copy of the Merle gene for it to be dominant and expressed on the French Bulldogs coat. It is not like the blue, chocolate, or cream Locus that need 2 copies the dilute for it to be expressed. So if a dog is blue and carries one copy of merle the dog will be a blue merle with merle pattern shown all over the French Bulldogs coat blue coat. When a dog is tan and point so (At/at) or( At/a) and carries no brindle gene the tan points are 100% visible on a merle dog. The Merle genes is lot more visible on a dog that has a dark coat such as brindle dogs (kbr/ky) or dogs that are tri color(at/at)(at/a) or solid black(a/a).

S-Locus  PieBald

The piebald gene is held at the S-Locus. It is a recessive gene so it needs 2 copies for the piebald to be expressed in the dog. For dogs that are dominate in Pied it is written as S/S. For dogs that are carriers of Pied it is written n/S. For dogs that are negative in Pied it is written as n/n.

 

Now how this all applicable when it comes to breeding? Great questions! Let me get into it already!

When being bread every Parent will give one gene from each Locus to its offspring (remember there are Locations in each Locus). So if a dog is a blue carrier and not a blue dog (D/d) its offspring will have a 50/50 chance of inheriting the Blue dilute gene or the empty Allele (D).  If a parent carries 2 copies of the blue dilute gene, the puppies will 100% carry at least 1 dilute genes. For the offspring to carry 2 blue dilute genes it will be up to the other parent to give it to them.  This goes for every Locus (color locations) the dog has.

 

Below are some of the colors possibilities.

DdBbata  kyky -Black and tan

DdBbatat  kyky -Black and tan (again since At/a and at/at is expressed the same in dogs, this dog and the dog above will look identical.)  

DdBbata kbrky – Black and tan Trindle

DdBbatat kbrky – Black and tan Trindle

ddBbata kyky -Blue and tan

ddBbatat kyky -Blue and tan (you get the point with the at/a and at/at)

ddBbata Kbrky -Blue and tan trindle

bbDdata kyky– chocolate and tan

bbDdata kbrky- chocolate Trindle

ddbbata kyky-Lilac and tan

ddbbata kbrky Lilac trindle

DdBbaa  kyky -Solid Black

DdBbaa kbrky -Solid Black (because and “aa” dog is solid black and no fawn in its coat expression it doesn’t let the brindle gene express itself.

ddBbaa kyky -Solid Blue dog

ddBbaa Kbrky -solid blue. (like above the dog has solid black coat that’s diluted by the blue dilute, so its solid blue. If a dog is At/a or At/At it allows the fawn in the dog to be expressed at the tan point location).  

bbDdaa kyky– Solid Chocolate

ddbbaa kyky-Solid Lilac