15-05-2025
The reason your ginger cat is likely to be male
The ginger gene for cats has finally been found and explains why 80 per cent are male.
For more than 100 years, scientists have suspected that the reason there are so many more male cats with orange fur lies in the X chromosome.
Male cats only have one X chromosome, so it was proposed that even if they only inherited one copy of a 'ginger gene' they would still have orange fur, whereas females would need two copies because they have two X chromosomes.
Scientists at Stanford University and Kyushu University in Japan have found that a mutation of the ARHGAP36 gene is responsible and it could also be linked to personality traits that owners have spotted in their pets.
Ginger males are often dubbed 'Velcro cats' because they are affectionate and less aloof than other breeds. However, ginger females are often considered aggressive and irritable, particularly when being handled, and are unfriendly with strangers.
According to Ontario Veterinary College, the pigment pheomelanin, present in cats with orange hues, is the same one that gives humans ginger hair, and science has shown that red-headed women have a lower tolerance to pain and discomfort.
There is speculation that it affects female cats similarly, which makes them more cautious and standoffish, especially with people they do not know.
Gene 'may influence more than coat colour'
Prof Hiroyuki Sasaki, a geneticist at Kyushu University in Japan, said: 'Identifying the gene has been a long-time dream, so it's a joy to have finally cracked it.
'Since it is active in many areas of the body, including in areas of the brain and hormonal glands, it's possible that the orange variant may cause shifts in gene activity elsewhere, influencing more than just coat colour.
'For example, 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.'
Prof Sasaki's team analysed DNA from 18 cats, 10 with orange fur and eight without. They found that all orange cats shared a specific deletion in the ARHGAP36 gene while the non-orange cats did not.
Further analysis showed that the mutation was linked to reduced activity in many genes involved in melanogenesis, the process that produces pigment in skin and hair.
The team believes the mutation may steer pigment production from dark eumelanin to lighter pheomelanin, creating orange fur.
Different from tigers
Female cats that inherit only one copy of the gene appear partially orange with a mottled pattern known as tortoiseshell, or with patches of orange, black and white known as calico.
The findings were backed by a second study from Stanford which also identified the same gene and found it is completely different to the mechanism that causes orange fur in other species, such as tigers or orangutangs.
Scientists believe that it was once rare in nature, but the adaptation may have made cats more appealing to humans, allowing the trait to proliferate with domestication. Orange cats are now widely distributed throughout the world.
Dr Christopher Kaelin, a senior scientist in genetics, said: 'This is something that arose in the domestic cat, probably early on in the domestication process.
'We know that because there are paintings that date to the 12th century where you see clear images of calico cats. So the mutation is quite old.'
The Stanford scientists believe that the differences in behaviour between ginger cats and other breeds may be less about genetics and more to do with them being largely male, but they could not rule out any impact from ARHGAP36.
'I don't think we can exclude the possibility that there is altered expression of the gene in some tissue we haven't tested that might affect behaviour,' Dr Kaelin said.
