The Finnish “Salmiak” Coat Color Discovery

A recent discovery from Finland has uncovered a completely new coat pattern and genetic variation. The Finnish domestic cat population has been found to have cats with a striking white and colored hair pattern, dubbed “salmiak. ” This new phenotype, which resembles a tuxedo cat with a unique white gradation in its coat, is caused by a previously unknown genetic variant associated with a large deletion in the KIT gene.

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What is the “Salmiak” Cat Coat?

The salmiak-colored cat is named after the Finnish term for “salty licorice” due to the cat’s distinctive color pattern. This pattern is most noticeable in solid black cats. However, can appear in other color backgrounds, such as brown tabby, tortoiseshell, and blue (dilution). The salmiak pattern features a mixture of white and color-gradated fur that starts with a solid color at the base of the hair, fading to white at the tips. The characteristic coloration is present from birth and remains stable throughout the cat’s life.

Although the salmiak pattern was first observed in 2007 in the Petäjävesi region of Finland, it has only recently been studied. A genetic cause has similarly only recently been studied.

Genetic Cause of the Salmiak Phenotype

The study of the salmiak cats led researchers to investigate the genetic background of this coat coloration. DNA samples were collected from five salmiak-colored cats. The team then used genetic sequencing methods to search for the gene responsible for the distinctive pattern. Interestingly, traditional tests for white coat patterns, which are commonly associated with the KIT gene, did not show the usual variants linked to full white or white spotting patterns. This led the researchers to focus on a different part of the genome.

Upon closer inspection of the genome, researchers found a sizeable 95-kb deletion. This was found in a region located approximately 65 kb downstream of the KIT gene. This is involved in developing melanocytes (cells responsible for pigment production). This deletion was associated with the salmiak phenotype. This is suggested to be the genetic cause of this unique coat pattern. The newly identified variant has been named “wsal” for “w salmiak”. This is to distinguish it from other known white coat-related variants in cats.

The KIT Gene and Its Role in Coat Color

The KIT gene significantly affects coat color patterns across various species, including cats. Known mutations in the KIT gene can lead to variations in the amount and distribution of melanocytes. These variations can cause different patterns of white coat color in cats. For example, cats’ well-known white coat patterns are typically caused by inserting a feline endogenous retrovirus (FERV-1) in the KIT gene. This causes full white coloration or white spots on the coat. The salmiak pattern, however, does not show these known insertions, which is why the discovery of the 95-kb deletion downstream of the KIT gene is significant.

Broader Implications for Cat Genetics

The discovery of the wsal allele is an important addition to cat genetics. It highlights the complexity and diversity of coat color patterns in domestic cats. This also opens up new avenues for research into the genetic basis of these variations. The study also suggests that new mutations, such as this one, could explain the occasional unique coat patterns seen in cats from various populations.

While the salmiak pattern is currently rare, the study’s findings offer valuable insight into the genetic underpinnings of coat coloration. Which may lead to further discoveries in the future. Additionally, this research could have practical implications for breeders and those studying the genetics of other feline traits, such as coat texture, behavior, and health.