English Bulldogs USA, LLC

Understanding Blue and Black English Bulldogs: Unraveling the DNA Sequencing

Overview

Blue Bulldogs, a captivating variant, are essentially diluted black dogs. Their blue/grey coat should exude shine and appear grey against black objects or in the sun, unless they carry the Seal gene, revealing maroon or other undertones. Notably, the nose, footpads, and eyeliner of Blue Bulldogs are always blue/grey, varying from light to dark, distinguishing them from black. There are so many variations of what a Blue or Black Bulldog is that it's impossible to capture each one uniqueness. With color modifiers you can have Full Suited Blue's or Black's (no or little white); Blue and Black Tri's/Trindles (a Tri with brindling); Blue and Black Seals; Blue and Black Merles with Tri/Trindle or Merles that are Cyptic (can hardly see it),   Blue and Black Harlequin Merle, or Blue and Black Tweed Merle; Blue and Black Platinums; Blue and Black Brindle; Blue and Black Pied; Blue Fawn/Sable. Please get your bulldogs DNA tested to find out exactly what color you have. 

Dilute/Blue Gene

• DD, Dd, dd

The gene d, recently renamed d1, plays a crucial role in dilute color phenotypes. Additionally, two more dilution MLPH variants, d2 and d3, have been identified. Two copies of any of these three dilution variants, or a combination of two, are necessary to lighten the coat color.

• Genetic Influence on Coat Color

The color of a dog's coat is governed by genes controlling the production of pigments (eumelanin and phaeomelanin) and their distribution. Understanding genetics, dominant vs. recessive genes, mutations, and alleles aids in predicting the color of puppies, making each dogunique.

• The K Locus and Alleles

The K locus in dogs has three alleles: KB (dominant black), kbr (brindle), and ky (non-black). Dominant black dogs (KBky or KBKB) exhibit solid eumelanin, while kyky dogs are "non-blacks," displaying a mix of eumelanin and phaeomelanin.

Black Bulldogs

• Commonality and Characteristics

Black Bulldogs, the most common of the 4 Rare Colors in AKC English Bulldogs, boast a shiny black coat. However, the presence of the seal gene can introduce different undertones. Tan points, typical in Tri Colors, are found on specific areas of the body.

• Tan Points and Genetics

Tan points may be hidden by other genes, such as the SEAL gene, and can bleed through on some dogs. Understanding the genetic makeup, including the presence of the [atat] gene, plays a role in displaying tan points.

Agouti Gene

• ay, at, a, aw

The Agouti gene, interacting with the MC1R gene, controls red and black pigment switching. Four known alleles—ay, aw, at, and a—determine variations in coat color, from fawn or sable to black and tan.

• Agouti Test

         The agouti test helps determine the color of dogs with white patterns that may obscure the distribution of colored pigment. Dominance and interaction with other genes contribute to the complexity of coat colors.

Check out this great PDF from Animal DNA Diagnostics 

Color Coat Modifiers

The base color of any Bulldogs can be enhanced with Tri points, brindle, seal, and merle, providing a unique aesthetic.

• Tri Points {at/at} the "at" Allele: Bulldogs carrying two copies of the at allele present a black and tan or tricolored coat. A tricolor dog is black-and-tan with white, and the at allele is always passed on to potential offspring.
• Brindle, Trindle, and Seal {K Allele}: The genes responsible for the brindle pattern are not fully understood. The K gene, specifically Kbr, plays a role in brindle patterns. The agouti gene overrides the brindle gene on the body coat, making it appear solid color. The K gene is visually inspected to determine if it's Kb (Seal) or Kbr (Brindle).
• Some Lilac Bulldogs may be both seal and brindle. The K gene, known as Dominant Black, is crucial for brindle patterns.
• Merle: This coat color pattern is characterized by splotchy patches of diluted colors. It is governed by a SINE insertion in the Pmel17 or Silver (SILV) gene. Merle only dilutes black pigment, and there are three alleles for merle: M allele, Mc allele, and N allele.
• Dogs with cryptic merle may display minimal merling and can be mistaken as non-merles. The inheritance of merle is genetically unstable for both M and Mc alleles.

Conclusion

Understanding the DNA sequencing of Blue Bulldogs involves unraveling the intricacies of dilution genes, the K locus, and the Agouti gene. The genetic makeup dictates the unique coat colors and patterns seen in English Bulldogs. It's crucial for breeders and puppy parents to grasp these genetic nuances for accurate color designation and appreciation of the breed's diversity. Remember DNA and the understanding of how colors are produces is an ever changing learning process. What is known today could be rewritten tomorrow. 

At English Bulldogs USA, LLC, we take pride in unraveling the genetic mysteries behind our Bulldogs. Each Bulldog is a testament to our meticulous breeding practices and unwavering dedication to preserving the unique qualities of this beloved breed. Written with help from Chat GPT.