→ The mutated gene is located on the X-chromosome, of which males only have one version while females have two. Because of its dominant inheritance, one copy of the BR1 variant is sufficient to exhibit the brindle coat texture. However, male horses do not show the brindle coat texture despite the mutation (semi-dominant).
- Brindle-1 is a coat texture with light and dark seeming alternating stripes, mainly caused by the hair structure, sometimes also by hair color.
- The stripes are V or S shaped and follow the so called “lines of Blaschko”.
- The mutation causes some hair to be more curly and rough in texture than others. They may also vary in color.
- Intensity of the pattern is highly individual and varies between individuals, seasons and coat length.
- In contrast to Incontinentia Pigmenti (IP), Brindle-1 has no known associated health issues.
- The pattern occures because in females one of two x-chromosome is inactivated. In some cells the mutated X-chromosome is inactivated (patches of normal hair) whilst in other cells the normal X-chromosome is inactivated and the mutated remains active (patches with rough hair).
- Homozygouse females with the Brindle-1 mutation (XBR1/XBR1) show additionally to the striped coat pattern sparse mane and tail.
- Hemizygouse males with the Brindle-1 mutation (XBR1/Y) do not develop the striped appearance but sparse mane and tail.
- Despite the name, this phenotype may not be confused or compared to the Brindle color pattern in dogs.
|X/X or X/Y
||No Brindle-1 variant.|
|XBR1/X||One copy of the Brindle-1 variant (female) → the mare has the brindle coat texture phenotype with individual intensity and color.
|XBR1/Y||One copy of the Brindle-1 variant (male) → the stallion has no brindle coat texture phenotype but sparse mane and tail.
|XBR1/XBR1||Two copies of the Brindle-1 variant (only females) → the mare has the brindle coat texture phenotype plus sparse mane and tail.
Testinformation: This test detects the change in theMBTPS2 gene.
Murgiano, L., Waluk, D., Towers, R., Wiedemar, N., Dietrich, J., Jagannathan, V., Drögemüller, M., Balmer, P., Druet, T., Galichet, A., Penedo, M.C., Müller, E.J., Roosje, P., Welle, M.M., Leeb, T. : An Intronic MBTPS2 Variant Results in a Splicing Defect in Horses with Brindle Coat Texture. G3 (Bethesda) :, 2016. Pubmed reference: 27449517. DOI: 10.1534/g3.116.032433.
Test #: H221
Samples: Blood, Hair
Price: 35 € (net)
Time required: 10-14 days