Scientists Develop New Dog Aging Calculator

Does one dog year really equal seven human years?  This long-held belief is undergoing some high-tech revision.

Scientists say a more accurate way to measure an animal’s age is to use something called an epigenetic clock—the accumulation of chemical modifications in an animal’s DNA over its lifespan.

One particular modification known as methylation is especially useful in tracking biological age.  DNA methylation has been used on humans and other animals, including mice, chimpanzees, and dogs.

Researchers at the University of California, San Diego have specialized in DNA methylation in dogs.  The researchers at UC San Diego studied over 100 Labrador Retrievers and found that their DNA methylation is somewhat similar to humans.

They also came up with an updated dog aging calculator, which shows that a dog’s “human age” can be calculated with a logarithm that multiplies a dog’s real age by 16, and then adds 31 to the total.

You can try the calculator HERE.

What does this new analysis of dog age mean?  Most dogs reach puberty at 10 months and live up to but not beyond 20 years.

The researchers found that a 7 week old puppy is roughly equivalent to a 9 month old human baby.  A 12 year old dog is roughly the same as a 70 year old human.

The researchers found that the canine epigenetic clock runs at a fast rate when a dog is young, then slows down somewhat as the dog grows older.

Scientists are hoping to apply DNA methylation to the study of how different dog breeds age, and also how certain diseases impact the various breeds.

 

The Genetics of White “Socks” in Our Pets

White paws, often called socks, are an endearing color marking in our pets.  Socks are often seen in cats, but can also be found in dogs and other animals like horses and guinea pigs.

Where do socks come from?  According to a recent article in Popular Science, which outlines some new scientific research on the genetics of coat color, white socks are a form of piebaldism (a genetic mutation that causes white patches of skin and hair).

Before birth, the cells that give color to a kitten’s eyes, skin, and hair (called melanocytes) are concentrated along the back.  During development, these pigment cells move to other areas of the body.

Sometimes the distribution is even, giving the cat a solid color.  But sometimes the color is spread unevenly, leaving white socks on the feet.  Many cats with white feet also have other white areas, such as the chest, belly, and part of the face.  Tuxedo cats are a good example of this.

Interested in learning more about the genetics of coat color in dogs and cats?  Check out this guide to coat colors and patterns in cats…and this one for dogs!

 

Home DNA Testing for Dogs Leads to Discovery of Genetics for Blue Eyes in Huskies

Many of us have ordered DNA testing kits for ourselves to learn about our ancestry.  But the boom in at-home testing is also spreading to our dogs.

An analysis of the home DNA tests of over 6,000 dogs (combined with photos and surveys from their owners) has led to the identification of a gene duplication on canine chromosome 18 that causes blue eyes in Siberian Huskies.

Duplication of a gene known as ALX4 (which plays a role in eye development) causes two blue eyes or one blue/one brown eye in both Huskies and non-merle Australian Shepherds.

A report on the study on the Science Daily website notes that the growing field of consumer genomics will lead to increased knowledge about our dogs, as well as ourselves.

You can read the full text of the research article HERE.

 

DNA Study Reveals What Happened to the Native Dogs of the Americas

A new study on canine genetics has been getting a lot of attention recently.  Do dogs living in modern North and South America retain the genes of the ancient dogs that accompanied the first Americans who came from Asia thousands of years ago?

A genetic study of the remains of ancient American dogs reveals that they were descended from the ancient dogs of Siberia (somewhat like today’s Arctic dogs such as Huskies and Malamutes) and not the native American wolf population.

These original dogs almost completely vanished after the arrival of European immigrants and their dogs in North and South America.  Only a tiny fragment of their genetic code lives on in modern American dogs…and you may be surprised to find out what it is.

Researchers have discovered that the closest surviving genetic link between these ancient dogs and modern dogs is the canine transmissible venereal tumor, which is a contagious cancer clone that can be traced to one individual dog that lived between 6,000 and 8,000 years ago!

You can learn more about this fascinating topic HERE.

 

Domestic Dogs Leave Genetic Pawprint on Wolves

We all know that our dogs are descended from wolves, but did you know that through continued interaction, domestic dogs have left a mark on the wild wolf population?

A recent international study of Eurasian grey wolves has found that 60% of these wolves carry some domestic dog DNA, proving that our pups have engaged in some amorous activity with their wild cousins over the centuries.

This intermingling of dog DNA in wolves is more common in Europe and Asia than in North America.

The researchers who conducted the study note that while wolf-dog interbreeding is a known phenomenon, the extent to which our dogs’ DNA has entered the wolf population is a bit of a surprise.

They say that our idea of what a “pure” wolf is needs to be revised, since so much hybridization has occurred.  A wolf that may look wild may actually be a hybrid with some dog DNA.

What have been the main causes of wolf-dog hybridization over the years?  Free-ranging (and unaltered) dogs, shrinking wolf population sizes, and unregulated hunting, say the experts.

Interested in learning more?  You can read the full article HERE.