Genetics explains Shar-pei wrinkles

The search for the genetic underpinnings of various phenotypes is a vast undertaking. As our knowledge of the relationships between genotypes and phenotypes matures, we have found more evidence that any particular phenotypic trait is encoded by the interactions of a host of genes, in concert with various environmental variables.

Given the vast complexity that geneticists have been slowly uncovering, it is always cheering to read about scientists localizing particular traits to a particular set of genes.

Especially if those traits and genes involve puppies.

The BBC reports that scientists have identified the genetic forces that play a role in giving the Shar-pei its distinctive wrinkled appearance. In particular, researchers have identified four single nucleotide polymorphisms located on the gene HAS2, which encodes an enzyme (hyaluronic acid synthase 2) known to be important for skin production (it makes hyaluronic acid, one of the principle components in skin). These SNP's were found while comparing a specific stretch of DNA between wrinkled Shar-peis, smooth coated Shar-peis, and other breeds. In addition, the group identified 155 genomic regions containing candidate genes for such phenotypes as are usually distinctive in breeds: size, coat color and texture, behavior, skeletal morphology, and physiology.

The full article is available at PNAS.