Researchers unravel Texas Longhorn genome

TexasLonghorn_blogThe Texas Longhorn has come a long way.

From the domestication of an ancient extinct predecessor to modern cattle to a trip to the New World with Spanish explorers, the history of this iconic cattle breed and a detailed trove of geopolitical history was hidden away in its genes until recently. To discover the Longhorns’ story, researchers at the University of Texas and the University of Missouri-Columbia worked through roughly 50,000 genetic markers from 58 breeds of cattle. It was the most in-depth analysis to date, according to the University of Texas.

The research, published in the Proceedings of the National Academy of Sciences, utilized genetic information garnered from samples run on BeadChips in Neogen’s GeneSeek laboratories.  These chips allow researchers and ranchers an inside look at the genetic history of individual animals.

“It’s a real Texas story, an American story,” said Emily Jane McTavish, a doctoral student who worked on the research with biology professor David Hillis.

Today’s Texas Longhorns are descended from animals brought over with none other than Christopher Columbus in 1493 and had made it to Texas by the end of the 17th century.

However, the Longhorn’s story begins much earlier. The researchers found that about 85 percent of the cattle’s genome is taurine, which comes from the wild aurochs, an animal that was domesticated in the Middle East between 8,000 and 10,000 years ago. The remainder of the Longhorn’s genome is indicine, which comes from aurochs domesticated in India.

The last known aurochs died on a Polish nature reserve in 1627 (although recently, scientists have looked at resurrecting it). They were enormous creatures – at more than a ton in weight and roughly six feet tall at the shoulder, aurochs would have dwarfed humans.

Cattle with more taurine features include Angus, Hereford and Holstein, whereas those with more indicine heritage often have a hump at the back of their neck. Taurine cattle eventually migrated from the Middle East to Europe, while indicine cattle moved from India to Africa, and eventually into the Iberian Peninsula (Spain and Portugal).

It’s on the Iberia Peninsula that researchers believe the taurine and indicine cattle intermixed during an extremely active time in history.

“It’s consistent with the Moorish invasions from the 8th to the 13th centuries,” Hillis said in a statement. “The Moors brought cattle with them and brought these African genes, and of course the European cattle were there as well. All those influences come together in the cattle of the Iberian peninsula.”

Fast forward to the 1400s, when Columbus brought cattle over on his trip to the New World – once there, many of the cattle became feral. Traits that had been bred out of previous generations, such as longer horns, began to reappear as animals with more robust horns could better defend themselves from predators. The cattle remained free on the range until the Civil War, when once again, they were brought back in for domestication, according to the University of Texas.

However, the long feral period helped out the Longhorns – they are immune to the tickborne disease cattle tick fever and have better resistance to drought conditions than do cattle brought to the U.S. later, the paper notes. Today’s Longhorns also  are prized for their iconic look, their parasite and disease resistance and their lean meat.

Read the full paper here.

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