Scientists have solved an age-old mystery about cats. Geneticists in Japan have discovered why eight out of ten ginger cats are male. A professor found that a mutation in the X chromosome is responsible for a previously unknown "orange gene". The professor said: "Identifying the gene has been a longtime dream." Male animals have an X and Y chromosome. If the male cat's X chromosome has the gene, it will be a ginger. A female cat has two X chromosomes. The gene needs to be present in both for the cat to be orange. This is less likely to happen.

The research has been published in the journal "Current Biology". In the study, researchers analysed the DNA of 18 cats, of which 10 had ginger fur. Only the ginger cats had the mutant gene. The professor said cat lovers associated fur colour with personality traits. He wrote: "Many cat owners swear by the idea that different coat colours and patterns are linked with different personalities. There's no scientific evidence for this yet, but it's an intriguing idea, and one I'd love to explore further." He suggested that ginger cats may behave similarly because most of them are male.