Black and Shades Thereof

Cattle that have a black nose have at least one ED allele at the E locus or MC1R gene. These cattle come in three shades: black, dun, and silver dun.

The shades are caused by a second gene that acts in a co-dominant pattern. There is a deletion (del) in the PMEL gene that causes a Highland to be dun instead of black if there is one del allele, and silver dun if both alleles are del.

Black

The Highland calf below is solid black, although she carries the red allele "e". Her genotype is ED/e. At PMEL she is +/+ or homozygous wild type, with no deletion.

Dun

The cow in front below, one of our key breeders Ronneach of Bairnsley, has one del allele at PMEL and one ED allele at MC1R. Her genotype is ED/e, del/+. She is called dun in Highland coat color terminology.

Silver Dun

Our Highland steer below is a silver dun. His genotype is ED/e, del/del.

Red and Shades Thereof

Red

Red can be caused by either an e/e genotype at MC1R, or an E+/e genotype. The E+ allele is common in Highland cattle and acts as if it were the most recessive of the three alleles at the E locus.

The Highland cow below, our Cailiach of Bairnsley, is red with an E+/e genotype. She is a deep red and therefore does not have a deletion at the PMEL gene, but is +/+.

Yellow

The cow below, our Siusan of Bairnsley,  is an example of a yellow Highland. Her genotype is e/e, del/+.

White

Our bull below, Lord Addams of Glenstrae is an example of a "white" Highland. His genotype is E+/E+, del/del. It is likely that cattle that are e/e, del/del may be even paler.

Brindle

Brindle cattle need at least one copy of the E+ allele at MC1R because that allele allows an animal to produce both the red phaeomelanin pigment and the black eumelanin pigment, instead of only one or the other. This young male Highland is a brindle. His genotype is E+/e. He has no deletion at PMEL and so his stripes are red and black, not paler versions of those colors.

Another mutation at another gene, ASIP is the main cause of brindle however. This allele is known as ABr. This mutation was discovered in a research lab in France, studying Normande or Normandy cattle. This Highland male has one copy of this brindle allele and one copy of the wild type or normal allele. His genotype is therefore ABr/A.

Brindle is harder to see as "stripes" in Highland cattle because of their long hair than in Texas Longhorn, for example. Highland cattle that have a del allele or two copies of the deletion allele and are brindle, and are even harder to see as striped.

The Highland cow below is homozygous for brindle, or ABr/ABr, and has the necessary E+ allele. It is E+/e. But it also has a deletion allele, del/+.

With thanks to the University of Saskatchewan

• Schmutz, S. M. and Dreger, D. L. 2013. Interaction of MC1R and SILV alleles on solid coat colors in Highland Cattle. Animal Genetics 44:9-13.
• Girardot M., Suibert S., Laforet M-P., Gallard Y., Larroque H., Oulmouden A. (2006) The insertion of a full-length Bos taurus LINE element is responsible for a transcriptional deregulation of the Normande Agouti gene. Pigment Cell Research 19, 346-355.