Source: Science
Scientists have identified the genetic basis for orange fur in cats and the unique coloration of calico and tortoiseshell patterns, solving a decades-long mystery. Two independent studies found that a mutation near the Arhgap36 gene, located on the X chromosome, increases the gene’s activity in melanocytes (pigment-producing cells), causing orange pigmentation. This mutation is shared by all orange, calico, and tortoiseshell cats.
The discovery sheds light on how female calico and tortoiseshell cats inherit two X chromosomes, with X inactivation creating distinct black and orange patches. Unlike other mammals, where red pigmentation is tied to the Mc1r gene, cats’ orange fur involves a novel molecular pathway. Experts are excited about the findings, noting that Arhgap36 is typically linked to embryonic development. The studies highlight how genetics influence cat coloration and suggest this mutation may have ancient origins, possibly appearing in early domestic cats. The research underscores the complexity of genetic interactions in animals.
Read the full story HERE: https://www.science.org/content/article/gene-behind-orange-fur-cats-found-last