A missing piece of code on one gene determines whether a cat turns red

It has finally been cleared with which gene red hair is related to cats. It was already known that the gene variant that corresponds with red cat coat had to be on the X chromosome, but now it is finally discovered where. In a gene called Arhgap36, it appears that a piece is regularly missing, and only cats where that piece is missing, have a (partly) red fur. There are now two articles about it in the scientific journal Current Biology: by Japanese and of predominantly American Researchers.

Katters only have one X chromosome and if the Rodevacht-Genvariant is on it, they are red. As a result, red cats (actually of course more orange) are more often males than cats. Drawers also realize that: Children’s book socket Dikkie Dik, Stripkater Garfield and the Rode you-Weet-Welkater from the Strip Jan, Jans and the children are bright orange colored.

Female cats still have a second X chromosome that can counterbalance against the Rodeverbachten variant. Laps cats (white and black with red) and turtle cats (spotty black with red) are almost always cats-or males with accidentally an extra X chromosome.

Embryonic phase

The patch and stain pattern of these cats is because in the embryonic phase, each cell randomly chooses one of the two X chromosomes to work with and the others almost entirely eliminates. That happens with every female mammal, also with people. It is called X-chromosome inactivation or lyonization, after the British geneticist Maryon who first described it in 1961 (in Nature). She already mentioned the « mosaic » coat of the turtle cat, which is created. The coat pattern of patch and turtle cats has since been the textbook example of lyonization, although it was unclear which gene mutation was related to the orange-red color.

The Japanese researchers discovered that mutation by first determining the entire genome of eighteen cats with various fur colors. In addition, they saw that a piece of non-coding DNA was missing in the Arhgap36 gene in cats with red hair. The researchers then confirmed the mutation in a few dozen other cats.

With patch cats, Arhgap36 only turned out to be active in red -haired skin tissue, while other genes were also active in the brown -black parts. The researchers therefore think that Arhgap36 becomes extra active due to the lack of the part of DNA, but what exactly the gene does has to be sorted out.

In an accompanying interview Standing research leader Hiroyuki Sasaki (University of Kyushu) that Arhgap36 has more functions than fur color. And that many people believe that cats with different fur colors have different characters. He wants to investigate that, although he also has to laugh about it. It is often said that red cats would be stupid: a cat community on Reddit, One Orange Braincellonly attributes them to one brain cell. However, there is no evidence for cat fur -color -related character differences, Sasaki emphasizes.

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