Dogs’ Golden Fur Evolved Two Million Years Ago, Long Before Domestication | Smart News


The shaded yellow phenotype produced by mutations on the ASIP gene is visible in the coat color of a Collie.

Certain dog breeds are prized for their unique coat colors, such as the shimmering, amber, or blue coat of the golden retriever. Blackbird Australian Shepherd spotted fur. Researchers previously thought that variations in coat color occurred after humans began breeding and domesticating canids. However, in a new study published this month in Nature ecology and evolution, researchers have found a gene that actually predates domestication produces five common coat color patterns that are still seen in hundreds of breeds today.

The mutations come from a canid ancestor that diverged from gray wolves about two million years ago, reports Vishwam Sankaran for the Independent. The study can also reveal the origin and evolution of various canine lines.

Dogs get their unique coat colors from a gene called agouti signaling protein (A SIP). The gene is responsible for controlling the amount and variation of yellow and black pigments seen in many mammals, reports Newsweek’s Samantha Berlin. The yellow tint is called pheomelanin and the black tint is called eumelanin. The color patterns of the coat result from a regulated production of these two pigments, the Independent reports.

A chart illustrating the five coat patterns - dominant yellow, shaded yellow, agouti, black saddle, and black back - and the corresponding breeds sporting the coloring

Examples of each coat pattern in modern dog breeds.

University of California, Davis (UC Davis) geneticist Danika Bannasch and her team have identified structural variants that control how the ASIP protein is expressed at two different locations on the gene. Mutations along the locations produce five different coat colors in dogs, according to a U.C. Davis Press release.

The five coat color variations, or phenotypes, controlled by the ASIP gene are dominant yellow, shaded yellow, agouti, black saddle, and black back.

The dominant yellow coat pattern is shared with arctic white wolves and found its way into modern-day dogs when the lineage diverged two million years ago before modern wolves evolved. Gizmodoit is Issac Schultz reports. The shaded yellow phenotype produced by mutations on the ASIP gene is visible in the coat color of a Collie. Agouti occurs when more than one pigment is present in each hair; this pattern is seen on German Shepherds, for example. A black saddle phenotype is characterized by a large black patch covering most of a dog’s back, which is commonly seen in beagles. Blackbacks are characterized by a black coat covering most of their body. Sometimes a black-backed dog will have a different colored belly or paws. This pattern is seen in breeds like Dachshunds or Bernese Mountain Dogs.

Lighter coat colors, such as dominant yellow and shaded yellow, may have favored the extinct canid ancestor when hunting in snowy environments during periods of glaciation between 1.5 and 2 million years ago. years, long before canine domestication 30,000 years ago, according to the Press release.

“We were initially surprised to find that white wolves and yellow dogs have a nearly identical ASIP DNA configuration,” says co-author Chris Kaelin of the HudsonAlpha Institute for Biotechnology in a statement. “But we were even more surprised when it turned out that a specific DNA configuration was over 2 million years old, before modern wolves emerged as a species.”

Through Newsweek, the lighter fur may have helped ancient wolves approach their prey unseen. A golden coat color persisted in ancient canids, and the coloration is still seen in modern dogs and wolves. Examples of dominant yellow coat patterns are seen today in Shiba Inus, Chow Chows, Bullmastiffs and Irish Terriers, Gizmodo reports.

Overall, the study gives scientists a better idea of ​​what ancient canines might have looked like, for example. Gizmodo.


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