Stumbled Science: Dog breeds with stumpy legs and the genetic event responsible
Ever wondered why some dog breeds have stumpy legs? Well it’s all down to retroduplication. Retroduplication is a genetic mechanism by which a gene can be duplicated using replicating machinery provided by retroelements within the human genome. So, what is a retroelement? vintage-calcium? hipster-helium? (Bad jokes). They are actually regions of the genome which can replicate themselves and are what makes our genome so big.
So back to tiny dog legs. In a common ancestor of 19 dog breeds including daschunds, corgis and basset-hounds a retroduplication of the gene fgf4 led to an increased number of copies which is attributed to the characteristic stumpy legs, termed chondrodysplasia.