Popular, ginger cats have no shortage of admirers. Whether it’s “Puss in Boots” in Shrek, our big Garfield, or even the sneaky Azraël in The Smurfs, red tomcats are very present to represent our feline friends, and are often preferred by animal lovers. cats.
And if this charming orange color had something to seduce, it also had something to intrigue: what was the secret of this color, and why was it linked to gender differences, most often expressed in males on red? classic, and in females on other variations?
After more than half a century of research, it seems that scientists have finally put their finger on the answers to these questions.
A missing segment of DNA
While delving into the mystery of ginger cats, Greg Barsh, a geneticist at Stanford University, and his team found something unexpected.
Using a panel of 188 cats brought together for this study, they observed that in cats with red coats, skin cells produced abnormally high RNA from a gene called Arhgap36.
But instead of finding an error in the part of the gene in question, they discovered that the sequence just before that gene was missing. This small “tear” in the DNA seems to disrupt the entire expression of the gene, explaining why ginger cats have this genetic peculiarity.
What was predictable was that this mutant gene is located on the X chromosome. This is why the red color does not appear in the same way in males and females. Most ginger cats (solid or bicolor) are male, while females often have a mixed coat, with spots of different colors, as can be seen in tricolors or tortoiseshells.
Males only have one X chromosome, so they have only one copy of this mutation. Females have two X chromosomes, one from each parent, and therefore two copies of the gene. In females, one of the two X chromosomes is randomly deactivated in each cell to prevent the cell from producing too much protein from that chromosome. This means that some female skin cells will express the red mutation, while others will not. In rare cases, if both X chromosomes have the mutation, the female will become as red as a male.
On another note, while ginger cats often have a reputation for being a bit special in terms of personality, there is no substantiated scientific evidence to date. Moreover, this mutation has no other consequences on their organism, other than the distribution of color.
If the Arhgap36 gene is known to cause developmental problems in other animals when it is poorly regulated, whether it is too active or not active enough, it does not actually seem to pose a problem in our cat friends. In our little felines, the gene seems to be overactivated only in the cells responsible for coat color, called melanocytes, whether they are developing or already mature.
Greg Barsh and his team explain that the difference between tortie and calico cats is an additional mutation that causes calicos to have white spots. This mutation affects the survival of pigmentation cells (melanocytes) as they migrate, and only those that manage to survive can spread to larger areas of the body, creating these white spot patterns.
In short, the ginger cat does indeed have an undeniable and very unique charm. Real rays of sunshine on legs, they have not finished making us fall in love!
