What is a dilute tortie cat?
A dilute tortoiseshell cat, commonly referred to as a dilute tortie, features a distinct coat colouration marked by grey and cream hues. This muted colour palette arises from a recessive dilution gene, which softens the traditional tortoiseshell’s bold black and red (or orange) tones.
The predominance of tortoiseshell cats among females stems from the location of the orange gene on the X chromosome. Male cats, with their XY chromosomal structure, have only one X chromosome and thus can either be orange or non-orange in colour. In contrast, female cats possess two X chromosomes (XX), enabling them to inherit both orange and black colour genes. Consequently, they manifest as tortoiseshells. When the dilution gene is present, the black and red pigments transform into softer grey and cream shades, resulting in the dilute tortoiseshell appearance.
This captivating blend of muted colours, influenced by distinct genetic factors, adds a nuanced dimension to the already complex world of feline genetics and coat variations.
Mode of inheritance
The dilute coat colour is governed by a recessive gene, signified as ‘d.’ For a cat to express this dilute colouration, it must inherit two copies of this recessive gene—one from each parent. In genetic notation, dominant genes are represented by UPPERCASE letters, whereas recessive genes use lowercase. Here, ‘D‘ stands for the dominant dense colouration, and ‘d‘ stands for the recessive dilute colouration.
- Homozygous Dense (D/D): In this genetic configuration, the cat will exhibit traditional, undiluted tortie colours, most commonly a mix of black and red, or less frequently, brown and red.
- Heterozygous Dense Carrying Dilute (D/d): These cats will also display the dominant tortie colours of black and red or brown and red, despite carrying one copy of the dilute gene. The dilute gene is masked by the dominant dense gene.
- Homozygous Dilute (d/d): A cat with two copies of the dilute gene will show softer, muted colours. Instead of black and red, the coat will be grey and cream, or in rarer cases, lilac and cream.
This genetic distinction helps to explain the variance in coat colours among tortoiseshell cats, including those that are dilute torties.
How the dilute gene affects coat colours
The muted hues observed in dilute-coloured cats are due to a single base deletion in the melanophilin (MLPH) gene. This gene is responsible for encoding melanophilin, a carrier protein vital for pigment distribution within melanocytes—cells specialized in melanin production.
Melanophilin operates within melanocytes’ organelles known as melanosomes. These melanosomes are crucial for synthesising, storing, and transporting melanin. They channel melanin through dendritic extensions to neighbouring keratinocytes, which are cells that produce keratin, the structural material of hair and skin.
In cats with the dilute gene, melanin synthesis occurs normally. However, the granules of melanin are abnormally large and unevenly distributed in the hair shaft. This irregular distribution leads to clumps of melanin in various sizes as well as sections of hair that lack pigment altogether. The end result is a coat that appears lighter in colour, creating the visual effect of a dilute or muted coat.
Effects of the dilute gene
| Dense | Dilute |
| Black | Grey (blue) |
| Red | Cream |
| Chocolate | Lilac |
| Cinnamon | Fawn |
Frequently asked questions
What breed is a dilute tortie?
A dilute tortie is a coat colour/pattern and not a breed and is found in both random-bred and purebred cat populations.
Are dilute torties rare?
Dilute torties are less common than the tortoiseshell pattern, which features more dense colours like black and red. Dilute tortoiseshells have softer, muted colours, typically grey and cream, as a result of a recessive gene that lightens the coat colour. Other dilute colour combinations, such as lilac and cream or fawn and cream, are less common and may be considered rarer.
How much is a dilute tortie worth?
The best place to adopt a mixed breed dilute tortie is from a rescue organisation or animal shelter, with an average cost of $100 to $300. This will include the first vaccination, worming, desexing and microchipping. A purebred dilute tortie can vary from $1,000 to $5,000 depending on the breed.
Are dilute tortie cats hypoallergenic?
Dilute torties are not hypoallergenic. Allergens in cats are found in their skin dander, saliva, and urine. While no cat is 100% hypoallergenic, some breeds like the Siamese, Balinese, and Russian Blue are often recommended for people with cat allergies because they are believed to produce fewer allergens.
If you’re allergic to cats and interested in getting a dilute tortie, your best bet would be to spend time with the specific cat you’re considering adopting to see if you experience any allergic reactions. Some people also find that female cats or neutered males produce fewer allergens, although individual responses can vary.
So, while a dilute tortie may be less allergenic if it belongs to one of these “hypoallergenic” breeds, its coat color itself doesn’t make it hypoallergenic.
Which breeds accept dilute tortie?
Dilute tortie can be found in the following breeds:
- American Wirehair
- British Shorthair
- Cornish Rex
- Devon Rex
- Exotic shorthair
- LaPerm
- Maine Coon
- Munchkin
- Norwegian Forest Cat
- Persian
- Scottish Fold
- Scottish Shorthair
- Sphynx
Are there any male dilute torties?
Dilute male torties are rare with an incidence of 1 in 3,000 and are usually associated with Klinefelter syndrome, a condition where the male inherits an extra X chromosome, ie; XXY instead of XY. Male torties are almost always sterile.
How long do dilute torties live?
The lifespan of a dilute tortie is the same as any other colour, with an average lifespan between 12-15 years. The lifespan of a cat is determined by genetics, diet, and if the cat is allowed to free roam or is kept indoors with or without an outdoor cat enclosure. Dilution does not play a role in how long a cat lives.
What is the personality of a dilute tortie?
Behavior in cats is influenced by a range of factors, including genetics, early socialisation, environment, and individual personality. While some studies have looked at whether coat colour correlates with behaviour, the findings are generally inconclusive or indicate that other factors are much more influential in shaping a cat’s temperament.
If you’ve heard that torties are more spirited or have more attitude, remember that these are generalisations that won’t apply to every individual cat. Many torties are very sweet, loving, and well-behaved, while others may be more spirited. Just like people, every cat is an individual, and their behaviour can’t be predicted solely based on their coat colour.
How do dilute torties differ from dilute calicos?
A dilute tortie’s coat features patches of muted colours like grey, lilac, or fawn and cream. In contrast, a dilute calico also has patches of white interspersed in its coat.
Feature image: Alena Mozhjer, Shutterstock