Scientists Identify the Genetic Origin of Ginger Cat Fur

Scientists have identified the genetic mechanism behind the orange coat colour in cats. Two independent research groups concluded that the colour is most likely caused by a missing DNA fragment in a part of the cat genome that does not code for proteins. The results were published in the scientific journal Current Biology.

Orange differs from most mammal coat colours because it does not follow the usual rules of inheritance. Until now, researchers had not managed to find the gene responsible.

What the researchers found

In skin cells that grow orange fur, a gene called Arhgap36 produces 13 times more RNA than in skin cells without orange fur. This difference was present in every orange cat the researchers examined, using a database of 188 cat genomes.

The link to sex

During the work, the teams also confirmed an earlier observation: the gene responsible for the mutation is located on the cat's X chromosome. This explains why the orange colour appears so differently in animals of different sexes. Most fully orange cats are males, while in females the orange fur usually appears only in separate patches of colour.

The discovery finally answers the question of which genetic change produces orange fur, and shows that it is tied to a part of the genome that does not itself code for proteins.