Golden colour variant specific to the Siberian and the Kurilian Bobtail, known as sunshine in its intermediate form and extreme sunshine in its homozygous form. It is characterised by a very wide golden band that produces a warm coat, almost uniform in extreme specimens. It is not associated with disease. It is distinguished from the golden of the British Shorthair by its probably different genetic basis.

Limited to the Siberian, the Kurilian Bobtail and related lines within the Russian standard. There are no reliable published allele frequencies; limited data. The frequency of extreme sunshine is higher in lines specifically selected for this variety.

- Warm golden coat with a wide band on each hair\n- Sunshine form: visible gold with residual tabby pattern\n- Extreme sunshine form: almost uniform gold with a very diffuse tabby pattern\n- No systemic manifestations

The sunshine phenotype became established in the Siberian breeding programme in the late 1990s and the early years of the 21st century, within the Russian standard of the breed. The molecular characterisation of the genetic determinants of golden in the Siberian has been associated with the CORIN gene in recent communications, distinguishing it from the classic wide-band described in other breeds. Extreme sunshine appears to correspond to the homozygous form of the responsible variant. The application of the same model to the Kurilian Bobtail is based on its genealogical proximity and the shared Russian standard. Limited data on the exact chronology and the peer-reviewed molecular reference publications.

- To fix extreme sunshine: mate extreme sunshine x extreme sunshine, or extreme sunshine x sunshine\n- Know the phenotype and, when available, the genotype of the breeding animals\n- Avoid mating with dominant silver (inhibitor I) if sunshine is to be maintained\n- Inform the buyer that it is an aesthetic trait with no pathological value

Differentiate sunshine from intermediate golden and from chinchilla; phenotypic assessment is subjective and may require inspection of the hair structure. There is debate about the genetic equivalence of sunshine with the golden of other breeds. Exclusive selection for extreme sunshine can narrow genetic variability if not planned.

1. Beauvois H et al. (2021) Siberian cats help in solving part of the mystery surrounding golden cats. Anim Genet 52(4):482-491. PMID: 33970502
2. Abitbol M et al. (2022) Golden cats: The story goes on. Anim Genet 53(4):543-545. PMID: 35574714
3. Lyons LA (2015) DNA mutations of the cat: the good, the bad and the ugly. J Feline Med Surg 17(3):203-219. PMID: 25701860
4. OMIA:002159-9685. Coat colour, golden in Felis catus. https://omia.org/OMIA002159/9685/