Decades-long mystery of ginger cats revealed

Esme Stallard
Climate and science correspondent

Garfield, Puss in Boots, and Aristocats’ Toulouse – iconic figures, possibly, definitely ginger. Scientists from two continents have now unraveled the DNA mystery behind the distinct coloration of our furry companions, especially males. The revelation that ginger cats lack a segment of their genetic code, leading to lighter skin, eye, and fur tones, has brought joy to both researchers and the numerous cat enthusiasts who initially crowdfunded the investigation.

The researchers are optimistic that solving this puzzle could offer insights into whether orange cats face elevated risks of specific health conditions. While it has long been known that genetics determine the unique coloring of orange tabby cats, the precise location in the genetic code had eluded scientists until now. Two teams from Kyushu University in Japan and Stanford University in the US have simultaneously unveiled the mystery in papers published on Thursday.

Their discovery revealed that a particular gene, ARHGAP36, was significantly more active in the melanocytes – cells responsible for a cat’s skin, hair follicles, and eye coloration. By analyzing the DNA of numerous cats with and without orange fur, the researchers found that ginger-colored cats had a missing section of DNA code within the ARHGAP36 gene, resulting in heightened activity of the gene and lighter pigment production by melanocytes.

For years, scientists have noted that fully ginger-colored cats are predominantly male, as the gene is carried on the X chromosome. This correlates with the fact that male mammals, including cats, possess an X and a Y chromosome, each carrying a different number of genes. With the gene controlling pigment production residing solely on the X chromosome, the absence of a DNA segment is adequate to render a cat entirely ginger. In contrast, female cats having two X chromosomes require the missing DNA in both chromosomes to achieve a similar increase in lighter pigment production, making mixed coloration more probable.

While the study delves into scientific intricacies, it was initially a personal project for Professor Sasaki, driven by his passion for felines. Despite retiring from his university position, Professor Sasaki, a devoted cat lover, embarked on uncovering the orange cat gene in hopes of aiding in the fight against feline diseases. Through crowdfunding, he and his team raised 10.6 million yen (£55,109) from numerous cat enthusiasts worldwide, including children contributing with their pocket money.

The ARHGAP36 gene, active in various body areas such as the brain and hormonal glands, is crucial for development. The researchers speculate that the DNA mutation in this gene could induce alterations in these body parts linked to health issues or temperament. Similar to cats, the ARHGAP36 gene is present in humans and has associations with skin cancer and hair loss. Professor Sasaki highlighted the unsubstantiated belief among many cat owners that distinct coat colors and patterns correspond to different personalities, expressing his curiosity in exploring this notion further.