Tag Archives: brachycephaly

DNA influences face shape

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 new insights into the genes that underpin skull formation in people 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 pet dogs of various pedigree and mixed breeds. The dogs were being treated at the Royal (Dick) School of Veterinary Studies.

All of the animals underwent body scans as part of their care, producing detailed 3-dimensional images of the dogs’ heads.  These high-resolution images — called CT scans — 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 were able to pinpoint DNA variations that are 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.

Babies are sometimes born with brachycephaly too, though little is known about its causes. Scientists say screening children for changes in the SMOC2 gene could help to diagnose the condition.

Lead researcher Dr Jeffrey Schoenebeck, of the University’s Roslin Institute, said: “Our results shed light on the molecular nature of this type of skull form that is so common and popular among dogs.”

Source:  University of Edinburgh news

Getting your head around dog genetics

Another public release of research this week.  This one from the Genetics Society of America about an article entitled ‘The Genetics of Canine Skull Shape Variation.’  Published in the February issue of Genetics, researchers review progress in defining genes and pathways that determine dog skull shape and development.

The researchers believe that the results are useful to humans because of the genetic expression of the features is likely to be similar process in humans as in dogs.

Skull shape is a complex trait, involving multiple genes and their interactions. Thanks to standardized canine breeding, which documents more than 400 breeds worldwide, and their distinct morphological features, researchers can disentangle traits such as skull shape, which in many breeds is a breed-defining variation.

Researchers are beginning to identify which genes cause a Bulldog or a Pug to have short pushed-in faces, or brachycephaly, and those that cause Salukis or collies to have narrow, elongated snouts, or dolichocephaly.

Source:  Genetics Society of America media release