Scientists locate DNA that makes canines of good companions

It is said that dogs are the best friend of man – and scientists have finally discovered what makes them the perfect companion.

Domestic pooches have a specific gene that means they are awake during the day rather than nocturnal like most wild dogs. wolves

The dogs probably developed the gene as they were domesticated to help them integrate into old human groups and become the loyal allies we know and love today.

The study sheds light on how a creature of thousands of years to become a beloved member of the human family.

Scientists from the University of Michigan have compared the DNA of modern wild dogs, ancient dogs found at burial sites around 5,000 years ago and wolves

. domestication of those related to the more recent development of specific breeds.

The review revealed 246 genes directly related to our old relationship with dogs – many for the first time.

One gene in particular had the strongest badociation with domestication – RAI1, which encodes a protein related to sleep and brain development.

In humans, protein plays a role in rare neurodevelopmental disorders in children who are also related to sleep disorders.

In dogs, modifications to this gene may explain why domestic dogs are awake during the day rather than at night like most wolves, the researchers said.

Co-author Shigeki Iwase said:

Humans and dogs worked together for at least 33,000 years, first by uniting shortly after humans emigrated in Europe.

Previous research has shown that dogs move several behaviors, including sleep, being active at the same hours as their owners meant that the dog could play and eat with his "pack".

Dr. Leslie Irvine, an animal expert at the University of Colorado at Boulder, told Live Science that dogs' ability to be active at the same time is part of what makes our relationship with them so strong .

She said: "Many behavioral factors predisposed dogs to easily integrate into human groups.

"They have a long period of primary socialization during which they can become closely related to humans."

In the new study, researchers undertook to separate the basic dog. the genes of those who have been introduced by the last three centuries of selective breeding.

Three quarters of the world's dogs are village dogs, who wander, feed on food near human populations and can mate more freely than

The team examined 43 dogs from village from places like India, Portugal and Vietnam and compared their DNA with that of wolves and remains of dogs dating back several millennia.

they identified the function, development and behavior of the brain.

RAI1 is involved in a specific type of brain cell called neural crest cell, and the researchers said their discovery could help scientists better understand the human brain is linked to the protein that it codes.

Professor Iwase said that in humans, RAI1 gene modifications result in one of two syndromes – Smith-Magensis syndrome if RAI1 is absent or Potocki-Lupski syndrome if RAI1 is duplicated.

"RAI1 is a good entry point in the study of brain function because its mutation causes a brain disorder," he said.

"One of the unique characteristics of these conditions is the problem that these patients have with sleep."