At its simplest, roaning means that white and pigmented hairs are intermixed. It's a striking coat phenomenon in which white hairs become intermixed with normally pigmented hairs, producing a mottled, frosted, or the famous “salt and pepper” appearance.
What's important to know early on while reading this is that roan coats are fundamentally different from a cat having white patches, white paws and muzzle, or progressive graying caused by either mutations or aging. In a roaned coat, the individual hairs themselves are important, as one hair is either fully pigmented or lacking heavily in pigmentation.
These hairs follow a pattern of black × white × black × white, which creates a diluted underlying coat that creates the illusion of grey fur being present.
Which brings us to our one and only guest, the amazing Lykoi ! Also known as the infamous werewolf cat :)
I won't dive too deeply into their origins and ethics because we're specifically learning about the origins of the roan coat, if you would like a more detailed post about lykois then please let me know !
lykoi Cats were the first breed to ever be recognised with a roan coat, that is due to the fact that many researches denied it before the first appearance of the breed when Patti Thomas discovered them.
At first the only permissible colour was black roan, as in black fur evenly interspersed with white hairs giving a grizzled grey colour. Lykoi breeders particularly favor dark coats to this day because the contrast makes the roaning extremely visible. It also enhances the physical image of the breed being "werewolves"
But even with that, many other coats still exist within the breed, and the black roan being a standard has long been casted away, as many lykois vary in shades and even colors !
Now the major gene implicated in Lykoi roaning is HR, which stands for Hairless, Cats' HR gene is involved in the biology of hair follicles and hair cycling.
In the Lykoi breed, researchers classified the Lykoi phenotype as a form of hypotrichia, meaning abnormally reduced hair growth. Their appearance is essentially the result of an interaction between abnormal hair growth and pigmentation mutations.
● OTHER ROAN CATS
Several cats with a blue-eye mutation were found in Russia and bred together as it was not realised that the mutations were different. Some of the cats had unusual bicolour markings and their initial black or blue markings appeared to turn grey as the colouyred hairs were replaced by white hairs. The roan pattern was not desirable in the breeds using the dominant blue eye genes and the cats were not bred from. This here is mochi, one of many cats with this phenomenon.
Another mutation that is still being studied is the famous Finnish Roan pattern, which resembles the original roan, but with far more white spotting. The mutation can also be called "black licorice mutation". This mutation has only been recorded to exist in Finland up until now, with a single exception of a cat being born in Russia.
The Finnish mutation pattern is recessively inherited, so it requires the genetic mutation to be inherited from both parents. The gene mutation is hidden in the parents. A recessive pattern can be carried a long way in cat generations without showing up, said Milla Salonen, PhD researcher at the University of Helsinki.
She added that cats who have inherited the Finnish mutation pattern are believed to be unable to reproduce but this is not confirmed because all known cats that have inherited the gene mutation came from wild populations and were neutered without having had the opportunity to reproduce.
And one other related mutation is the karpati coat, often mistaken with "kitten fever" coats, the karpati pattern is caused by a dominant gene, which occurs naturally among non-pedigree cats around the Carpathian Mountains in Eastern Europe.
Cats with the gene have white hairs mixed in throughout their coats, but with a greater concentration of white hairs on the points (which could suggest some sort of temperature sensitive effect.) It can be combined with any other colour or pattern, but the best contrast is seen on dark, solid colours.
the karpati pattern has spread significantly in Slovakia and the Czech Republic and is now a defining feature of the Transylvanian breed in Romania. The pattern has also been introduced into a number of breeds such as the LaPerm.
