K-Locus Genetics
Brindle French Bulldog Patterns
The complete guide to the K-locus brindle gene (Kbr). How brindle patterns are produced, reverse brindle explained, and brindle combinations with other colors.
Predict Brindle OutcomesWhat Is the K-Locus?
The K-locus controls pattern expression in French Bulldogs. It has a three-allele hierarchy that determines whether a dog shows solid black, brindle stripes, or its base A-locus color.
Kb (Dominant Black)
The top of the hierarchy. Kb produces solid black coat regardless of A-locus. If a dog carries Kb, brindle and fawn are both hidden.
Kbr (Brindle)
The middle allele. Kbr produces brindle striping when no Kb is present. Creates tiger-striped patterns overlaying the fawn base.
ky (Non-Brindle)
The bottom allele. ky allows the A-locus color to show directly — fawn, sable, or tan points with no brindle pattern.
K-Locus Genotype Hierarchy
The K-locus follows a strict dominance hierarchy. Higher alleles always mask lower ones.
Brindle Variations & Combinations
Brindle is a pattern overlay, not a base color. When combined with other color genes, it creates stunning and valuable variations.
Black Brindle
Kbr/ky
The classic brindle: black stripes on a fawn base. Most common brindle pattern in Frenchies.
$2,500 – $5,000
Reverse Brindle
Kbr/ky
Dense dark stripes with thin fawn lines showing through. Creates a nearly black appearance with subtle striping.
$3,000 – $6,000
Blue Brindle
Kbr/ky + d/d
Brindle stripes in blue-gray instead of black. Requires the dilute gene at the D-locus.
$4,000 – $8,000
Chocolate Brindle
Kbr/ky + b/b
Brindle stripes in chocolate brown instead of black. Requires the chocolate gene at the B-locus.
$5,000 – $9,000
Lilac Brindle
Kbr/ky + d/d + b/b
Brindle stripes in silvery-lilac. A rare combination of brindle + dilute + chocolate.
$7,000 – $15,000
Cream Brindle
Kbr/ky + e/e
Very light brindle pattern on a cream base. Subtle and elegant. The e/e masks much of the pattern.
$3,500 – $6,000
Predict Brindle Patterns
Our DNA Calculator models K-locus outcomes alongside D, B, E, A, S, M, and L loci. See exactly which puppies will be brindle, fawn, or solid black.
Open the DNA CalculatorFrequently Asked Questions
What is a brindle French Bulldog?
A brindle French Bulldog has a coat pattern produced by the K-locus gene. The Kbr allele creates a tiger-striped or marbled pattern where dark stripes overlay a lighter base color — typically black stripes on a fawn or cream background. Brindle is one of the most common and recognizable Frenchie patterns, and it is an AKC-recognized standard color.
How is brindle produced genetically?
Brindle is produced by the K-locus gene. The Kbr allele is dominant over non-brindle (ky) but recessive to the dominant black allele (Kb). A dog with Kbr/Kbr or Kbr/ky shows brindle patterning. A dog with ky/ky shows no brindle and instead expresses its A-locus color (fawn, sable, or tan points). Brindle can overlay on any base color, creating variations like blue brindle, chocolate brindle, or reverse brindle.
What is reverse brindle?
Reverse brindle is a pattern where the dark stripes are so dense and prominent that they appear to be the base color, with the lighter fawn showing through as thin stripes. It creates a visually striking 'dark tiger' appearance. Reverse brindle is genetically identical to regular brindle (Kbr/ky or Kbr/Kbr) — the difference is simply the ratio of dark to light pigment in the individual dog's coat.
Can brindle Frenchies carry other color genes?
Yes. Brindle is a pattern overlay, not a base color. A brindle Frenchie can also carry dilute (D/d or d/d), chocolate (B/b or b/b), cream (E/e or e/e), and other color genes. For example, a dog with Kbr/ky + d/d shows a blue brindle pattern — brindle stripes in blue-gray instead of black. These stacked genes create the many brindle variations seen in the breed.
How much does a brindle French Bulldog cost?
Brindle French Bulldogs are typically the most affordable color because brindle is common and AKC-recognized. Prices range from $2,500 to $5,000 for pet-quality brindles. Breed-quality brindles with full health clearances and champion bloodlines range from $4,000 to $6,000. Reverse brindle and rare brindle combinations (blue brindle, chocolate brindle) may command slightly higher prices.
Is brindle dominant or recessive?
The brindle allele (Kbr) is dominant over non-brindle (ky) but recessive to dominant black (Kb). The K-locus hierarchy is: Kb (dominant black) > Kbr (brindle) > ky (non-brindle). This means a dog with Kb/Kbr shows solid black, not brindle. Only dogs without Kb can show brindle if they carry Kbr. Dogs with ky/ky show neither black nor brindle — they express their A-locus color directly.