Garfield’s mutation – solved the genetic mystery

Garfield the famous orange cat should feel proud: After decades of fruitless search, geneticists have managed to identify the mutation that this unusual color gives to some cats.

The orange shade is due to the loss of a small genetic sequence that affects melanin production, reveal two independent studies in the Current Biology Inspection.

Garfield’s mutation – solved the genetic mystery of orange cat

Cats that have a uniform orange hair throughout the body are more common male, which has long led to the conclusion that an unknown « orange gene » is hidden on the X chromosome, which exists in male cats only in one copy, what they inherited from their mothers.

Female cats have two copies of X and must inherit the gene from both parents to be uniform orange, which happens much rarer.

Even when female cats carry two copies of the gene in question, the orange color appears only in patches on their bodies, as is the case with « Kalico » cats. This is because one of the two X chromosomes is accidentally switched off in each cell, as is the case in humans.

« The phenomenon is so apparent that it is considered a typical example of the X chromosome deactivation, although the gene involved has remained unknown, » said Grujuki Sassaki of the University of Kyoussos in Japan, head of the head of Japan. first of the two studies.

The Sassaki, who declares a cat lover, raised about $ 60,000 through crowfunding campaigns to finance the study, which involved genetic analyzes in 10 orange cats and 8 without.

The analysis showed that all orange is due to a mutation of the Arhgap36 gene, which is involved in a wide range of biological functions.

The mutation does not change the synthesis of the protein encoded in the gene, but it increases the expression of the ARHGAP36 gene. This change seems to force the skin cells to produce light pheomelanin instead of dark emelanine. As a result, the hair becomes orange.

In the same findings the second studywhich is signed by researchers at Stanford University.

Since ARHGAP36 is expressed in many organs, such as the brain and the endocrine glands, the orange mutation is not excluded that it affects other cat characteristics beyond the color.

« For example, many cat owners swear that the different colors and patterns of the hair are linked to personality differences, » the chassis commented.

« There is still no scientific evidence of this, but it is an interesting idea that I would like to consider, » he added.

The researcher is also curious to find out when the orange mutation appeared.

« One idea would be to study cat illustrations from ancient Egypt, or even perform DNA tests in mummified cats, » he said.