Table 4.
Major Mendelian pigmentation loci and associated genes and phenotypes in dogs and cats.
| Locus/category | Gene | Allelea | Phenotype |
|---|---|---|---|
| DOG | |||
| Spotting | |||
| S (Spotting) | MITF | ||
| S | Solid coat (no spotting, wild type) | ||
| si | Irish spotting pattern | ||
| sp | Piebald spotting pattern | ||
| sw | Extreme white spotting pattern | ||
| T (Ticking) | Unknown | ||
| T | Ticking in white areas | ||
| t | No ticking (wild type) | ||
| M (Merle) | PMEL | ||
| M | Merle pattern | ||
| m | Non-merle (wild type) | ||
| Dilution | |||
| B (Brown) | TYRP1 | ||
| B | Black – no dilution of eumelanin (wild type) | ||
| b | Liver, brown, chocolate – diluted eumelanin | ||
| C (Albino) | Unknown | ||
| C | No dilution of pheomelanin (yellow, sable, fawn, wild type) | ||
| cch | Dilution of pheomelanin (white, cream) | ||
| H (Harlequin) | PSMB7 | ||
| H | Harlequin pattern (in a merle background) | ||
| h | Merle pattern (in a merle background) | ||
| Tw (Tweed) | Unknown | ||
| Tw | Large smooth patches (in a merle background) | ||
| tw | Small, jagged patches (in a merle background, wild type) | ||
| Pigment-type switching | |||
| A (Agouti) | ASIP | ||
| Ay | Yellow, sable, fawn | ||
| aw | Agouti-banded hair, light colored ventrum | ||
| at | Black-and-tan | ||
| a | Recessive black | ||
| K (Kurokami) | CBD103 | ||
| KB | Black | ||
| kbr | Brindle (black and yellow stripes) | ||
| ky | Wild type (allows expression of Agouti phenotypes) | ||
| E (Extension) | MC1R | ||
| Em | Melanistic mask | ||
| E | Extension, wild type | ||
| e | Recessive yellow | ||
| CAT | |||
| Spotting | |||
| W (White) | KIT | ||
| W | White coat | ||
| Wh | High degree of spotting | ||
| Wl | Low degree of spotting | ||
| w | Solid (wild type) | ||
| Dilution | |||
| B (Brown) | TYRP1 | ||
| B | No dilution of eumelanin (black, wild type) | ||
| b | Chocolate | ||
| b1 | Cinnamon | ||
| C (Albino) | TYR | ||
| C | No dilution of melanin (yellow, sable, fawn) | ||
| cb | Burmese (temperature-sensitive dilution pattern, pointed coat) | ||
| cs | Siamese (temperature-sensitive dilution pattern, extreme pointed coat) | ||
| c | Albino | ||
| Pigment-type switching | |||
| A(Agouti) | ASIP | ||
| A | Agouti-banded hair (wild type) | ||
| a | Recessive black | ||
| E (Extension) | MC1R | ||
| E | Extension (wild type) | ||
| e | Amber, age-dependent fading of tabby pattern | ||