Brachyury (Bobtail)

This mutation for short-tailedness, called Brachyury or Bobtail, was originally discovered in the Pembroke Welsh Corgi, but also causes distincive short tails in multiple other breeds, mainly sheepdogs and hunting breeds. The mutation itself is a defect in the T gene. The short-tailed trait is dominant, but the mutation is recessive lethal, meaning that only carriers and unaffected dogs will be born. This mutation is not the cause for short tails in certain other breeds, including Spaniels, Schnauzers and Rottweilers.