Coat Colour O-Locus (Orange)
Code: K510
Short description
The O-Locus is associated by a deletion in the ARHGAP36 gene, which is found on the X-chromosome.
General information
The O-Locus is associated by a deletion in the ARHGAP36 gene, which is found on the X-chromosome. This O-Locus causes the suppression of black-brownish pigmentation in favor of orange coloration. In domestic cats, this leads to a mosaic of reddish-yellow fur patches, as found in female tortoiseshell and calico cats.
Specifications
| Breeds | All Breeds |
|---|---|
| Gene | ARHGAP36 |
| Organ | Integumentary System |
| Specimen | Copan eNAT swab, Blood EDTA, Blood Heparin, Semen, Tissue |
| Mode of Inheritance | X-linked |
| Chromosome | X |
| Year Published | 2018 |
Clinical features
The O-locus has an X-linked inheritance meaning that expression differs in female and male cats. Tomcats only have one X-chromosome, and therefore have only one variant present. If it has the orange mutation the colour will be orange/ginger (apart from other loci that may influence the coat colour). Females have two X-chromosomes and thus two alleles. They need two mutated alleles, one from each parent to show a complete orange colour. If a female has only one mutated allele it expresses only patches of orange as found tortoiseshell and calico cats. The mosaic patches are a result of random X-inactivation (XCI).
Tortoiseshell and calico males do occasionally occur, but it’s usually due to an abnormality of the number of sex chromosomes (such as XXY).
Additional information
Coat colour is an intricate trait that involves a combination of multiple different genes. Testing for a range of different loci will give the most complete prediction of a cat's coat colour genetics.
References
Pubmed ID: 39605675
Omia ID: 1201
Turnaround information
- 15 working days