Gold coat colour (sunshine, extreme sunshine) in Siberian cat

The Siberian cat has a wide range of coat colours. It can be solid or patterned. The Wb+ (wide banding) allele leads to an enlargement of light areas of the coat, especially in tabby cats. The coat thus appears softer and lighter. The vwb^SIB allele causes enlightenment of these lighter areas and the coat to take on a warm and glowing tone reminiscent of sunshine. The most pronounced lightening is caused by the vwb^eSIB allele. The coat colour is very bright, light, almost white and the pigment is concentrated only in the tips of the hairs.

The golden 'sunshine' colour is caused by missense mutation c.2383C>T in the CORIN gene, while the 'extreme sunshine' colour is caused by missense mutation c.839G>A in the same gene. The CORIN gene encodes a transmembrane serine protease that acts as a suppressor of the ASIP pathway, which controls the production of eumelanin and pheomelanin, respectively.

Inheritance of both mutations is autosomal recessive. This means that the trait develops only in individuals who inherit the mutated gene from both parents (recessive homozygotes). Heterozygotes are carriers who pass the mutation on to their offspring. The genotype of an animal can be clearly revealed by a genetic test.

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References:

Beauvois, H., Dufaure de Citres, C., Gache, V., Abitbol, M. : Siberian cats help in solving part of the mystery surrounding golden cats. Anim Genet 52:482-91, 2021. Pubmed reference: 33970502.

Abitbol, M., Dargar, T., Gache, V. : Golden cats: The story goes on. Anim Genet 53:543-545, 2022. Pubmed reference: 35574714.