A study of dog DNA has revealed a genetic mutation linked to flat face shapes, such as those seen in pugs and bulldogs.
The research reveals insights into the genes that underpin skull formation in humans and animals.
Scientists say their findings also shed light on the causes of birth defects that affect babies’ head development in the womb.
Researchers at The University of Edinburgh’s Roslin Institute analysed DNA samples from 374 pedigree and mixed breed dogs being treated at the Royal (Dick) School of Veterinary Studies.
All of the animals underwent body scans as part of their care, producing detailed 3D images of the dogs’ heads. These high-resolution images enabled the researchers to take precise measurements of the shape of the dog’s skull.
By comparing the dogs’ genetic information with measurements of their skulls, the team was able to pinpoint DNA variations associated with different head shapes.
One variation – found to disrupt the activity of a gene called SMOC2 – was strongly linked to the length of the dog’s face. Animals with the mutation had significantly flatter faces, a condition called brachycephaly.