Orange cat coat genetic discovery

In early July 2026, scientists reported that they had isolated the genetic factor responsible for orange fur in domestic cats. By the end of the month, detailed studies from Stanford University in the United States and Kyushu University in Japan were published in *Current Biology*. Both teams identified a roughly 5,000‑base‑pair deletion in a regulatory region of the X‑linked gene **ARHGAP36**. The deletion acts as a switch that increases production of the pigment feomelanin while suppressing eumelanin, producing the orange coat. The research also clarified why orange cats are predominantly male: the X‑linked mutation causes the phenotype in males with a single altered X chromosome, whereas females would need the mutation on both X chromosomes to express the colour. These findings resolve a long‑standing question about the inheritance and molecular basis of orange fur in felines.