Cat coat genetics: How kittens inherit fur color
Table of contents
Level: School to college · Start here: cat coat color calculator
Cat coats are one of the best real-world ways to learn genetics. A handful of well-studied genes explain most of the colors you see in pet cats, and between them they cover nearly every pattern in a genetics course: dominant and recessive alleles, multiple alleles, X-linked genes, one gene hiding another, and genes that respond to temperature.
This is CrossCalc’s cat genetics section. Start with the calculator, or pick the coat you’re curious about. Many of the same genes turn up in the mouse genetics section, so the two make a good pair.
Pages in this section
Tool
- Cat coat color calculator: choose each parent’s genes and see the chance of every kitten coat, split into daughters and sons, with a Punnett square for each gene.
Coats, one gene at a time
- Calico and orange cats: the X-linked Orange gene, X-inactivation, why calicos are almost always female and why most orange cats are male. High school.
- Siamese (colorpoint) cats: a heat-sensitive enzyme that colors only the cooler points, plus Burmese sepia and mink. High school.
- Dilute (blue) cats: one recessive allele that turns black to blue, chocolate to lilac and orange to cream. School to high school.
- Tabby cats: how agouti decides whether a pattern shows, and mackerel, classic, spotted and ticked tabbies. School to high school.
- White cats and deafness: dominant white, blue eyes and what hearing studies found. School to high school.
What each gene teaches
| Gene | What you see | Genetics idea it teaches |
|---|---|---|
| Orange (on the X chromosome) | Orange, tortoiseshell, calico | Sex linkage and X-inactivation |
| Brown (TYRP1) | Black, chocolate, cinnamon | Multiple alleles in a dominance series (B > b > bl) |
| Dilute (MLPH) | Blue (gray), lilac, fawn, cream | A recessive allele that modifies other genes’ colors |
| Agouti (ASIP) | Tabby vs solid | One gene controlling whether another gene’s pattern shows (epistasis) |
| Tabby pattern (TAQPEP) | Mackerel vs classic stripes | Simple dominance |
| White (KIT) | All white, or white patches | Dominant white hides every other color gene; one gene, several alleles |
| Colorpoint (TYR) | Siamese and Burmese points | Gene–environment interaction (a heat-sensitive enzyme) and codominant alleles (cb/cs mink) |
| Hair length (FGF5) | Short vs long hair | Simple recessive trait |
Three quick examples
A black tom and an orange queen. Every daughter is tortoiseshell and every son is orange, because sons get their only X from their mother. (See the squares.)
Two black cats with a blue kitten. Blue is black with two copies of the recessive dilute allele (d/d). So both parents must carry d: they’re D/d, and each kitten has a ¼ chance of being blue. It’s the same 3:1 logic as a monohybrid cross.
Two full-colored cats with a Siamese-pointed kitten. Both parents carry the colorpoint allele cs (C/cs). The kitten is cs/cs, so its pigment enzyme works only in the cooler parts of its body: the ears, face, paws and tail.
Why cats, and what to watch for
Cats work well for teaching because the genes are known, the effects are visible, and there’s no awkward human-health framing. Two cautions keep the model honest:
- Real cats are more varied than the simple model. The amount of white, the clarity of tabby markings and the shade of points all vary, and there are more genes and alleles than any classroom table includes.
- Coat color isn’t behavior or health. Claims about personality by coat color aren’t genetics. The best-known health link is that dominant white cats, especially blue-eyed ones, have a higher chance of deafness (white cats and deafness).
Related
- Beyond Mendelian inheritance: the exceptions cats illustrate so well
- Mouse genetics: the mouse section, with many of the same genes
- How to write genotypes and alleles
- Dihybrid cross calculator
- Genetics glossary: plain definitions of allele, locus, genotype and more
Sources
- UC Davis Veterinary Genetics Laboratory, Feline coat color.
- Kaelin CB, et al., Barsh GS. “Molecular and genetic characterization of sex-linked orange coat color in the domestic cat.” Current Biology 35, 2826–2836 (2025). doi:10.1016/j.cub.2025.04.055
- Toh H, et al., Sasaki H. “A deletion at the X-linked ARHGAP36 gene locus is associated with the orange coloration of tortoiseshell and calico cats.” Current Biology 35, 2816–2825 (2025). doi:10.1016/j.cub.2025.03.075
- Górska A, Zieniuk B, Wojciechowska M. “Colour Variants in Siberian Cats: A Comprehensive Review of Phenotype, Genetics, and Breed Registry Standards.” Genes (2026). PMC12941195
- David VA, et al. “Endogenous retrovirus insertion in the KIT oncogene determines white and white spotting in domestic cats.” G3 (2014). doi:10.1534/g3.114.013425
- Lyons LA, et al. “Tyrosinase mutations associated with Siamese and Burmese patterns in the domestic cat.” Animal Genetics (2005). doi:10.1111/j.1365-2052.2005.01253.x