According to legend, the Shar-Pei’s purple tongue and wrinkled skin gave ghosts “the willies.”  Indeed, having a Shar-Pei in the house, it was believed, ensured that those who lived there could sleep easy knowing they were in a “spectral free zone.”

Try as we might, we couldn’t find a fairy tale surrounding why the Shar-Pei got his wrinkles, but we’re betting there’s a good one out there. For now, we have to content ourselves with something less lyrical, the real reason why the Shar-Pei has wrinkles.

Mucin.

A Shar-Pei’s wrinkles are caused by the hyaluronic acid synthase 2 (HAS2) gene which encodes an enzyme synthesizing hyaluronan, a major component of the skin that is up-regulated and accumulates in the thickened skin of the dog. It’s considered to be the main component of mucin, and with CD44 (the major cell surface receptor of HA necessary for its uptake and catabolism), it is the large amounts of mucin that give the Shar-Pei’s skin its flexibility and wrinkles. The skin itself tears relatively easily, but it also heals quickly and with a minimal amount of scarring.

In “See Spot Run” terms, hyaluronan is kind of gel that surrounds the skin cells. It helps with skin hydration and elasticity (among other things), but in a Shar-Pei, the HAS2 gene acts as if it’s on “speed” by creating too much hyaluronan,  and that causes the breed’s famous wrinkles especially visible in Shar-Pei puppies.

Not as romantic as a fairy tale, but fascinating nonetheless.

Photo of Shar-Pei puppy/DepositPhoto