FOXI3 (Hr gene)

FOXI3 is a gene that guides the development of hair, skin and teeth. In the Chinese Crested, a dominant mutation in FOXI3 causes hairlessness, and the mutation is often called the Hr gene. Dogs with one copy are hairless, and dogs without it are powderpuffs.

What is FOXI3?

FOXI3 is a transcription factor, a gene that regulates other genes during embryonic development. The link between FOXI3 and hairlessness in dogs was published by Drögemüller and colleagues in Science in 2008.

Why does it also affect teeth?

The gene is involved in the development of skin, hair and teeth. This is why FCI standard 288 says hairless dogs should not be penalised for incomplete dentition.

What does it mean for breeding?

The mutation is homozygous lethal: puppies with two copies do not survive. Hairless dogs are therefore bred to powderpuffs in practice. See DNA testing.