Brindle is a pattern of stripes,which can be red and black,fawn and black, isabella and gray. It occurs in Great Danes,Greyhounds,Boxers, et al and sometimes Ridgebacks. The K locus plays a pivotal role in coat color. This locus is a relative newcomer in our understanding of canine color, and includes traits formerly attributed by some to other genes.
The dominant allele in the series is KB, which is responsible for self-coloring, or solid colored fur in pigmented areas. This trait was formerly attributed to the Agouti (A) locus as AS, but recent breeding studies had shown this not to be the case.
There are two other alleles, kbr, and ky. KB is dominant to both kbr and ky, while kbr is dominant only to ky. kbr is responsible for the brindle trait and for a long time had been considered to belong in the E locus. Recent breeding studies had also shown this to be incorrect. The recessive allele, ky, allows the basic patterns of the A locus to be expressed. So too does the kbr allele, but with brindling of any tan, fawn, or tawny areas.
Any animal with at least one KB allele will be self-colored.Any animal with at least one kbr allele, and no KB allele will be brindled on agouti background (see A locus).Any animal with two ky alleles will show agouti patterns (see A locus).
The mutations responsible for these alleles were identified and described primarily by Sophie Candille in the laboratory of Dr. Greg Barsh at Stanford University Thanks to Jabulani RRs for this photo.
Here is another example of the brindle coat, which was originally in accord with the standard
