COLLEGE STATION - Scientists at Texas A&M University have successfully cloned what is believed to be the first calf cloned from an adult bull, which is also the oldest animal ever cloned - a 21-year-old Brahman. Their research could have enormous implications in the beef cattle industry and in the future applications of cloning technology.
Researchers Jonathan Hill and Mark Westhusin accomplished the cloning of the bull, fittingly named "Chance," in a year-long project. Chance's offspring, "Second Chance," was born three weeks ago and displays identical markings as his father and has identical DNA, the researchers say.
"The owners of Chance, who are from LaGrange, Texas, wanted to have their prized bull cloned because of his unusually gentle nature, and they considered the cloning effort a good opportunity to see if an identical copy of Chance might also have such an easy going disposition," Hill said. "Chance was great around people, and he was in several TV commercials, performed in the Houston Rodeo and was even on The Late Show with David Letterman," Hill added "They are looking forward to seeing if Second Chance lives up to his heritage." Hill said the bull was unable to reproduce naturally because of the removal of both diseased testicles two years ago. Therefore, he said, cloning Chance was the only option for preserving his genetics. "Second Chance is obviously an intact male and should be able to sire offspring when he reaches puberty," Hill confirmed. Chance died a few months ago at age 21, shortly before his DNA was used to produce Second Chance. Hill said there is considerable interest in keeping track of Second Chance throughout his lifetime because of the age of the cells used to clone him. Last spring, scientists revealed that the DNA of Dolly, the first cloned sheep, had some characteristics of the older cells that were used to generate her.
"The chromosomes, which package the animal's DNA, have some special DNA at their tips called telomeres," Hill explained.
"These small pieces of DNA help to protect chromosomes from damage. Very young animals have long telomeres, but as the animal ages, the telomeres are worn away. We should know in a month or so if the telomeres of Second Chance are like those of the 21-year-old bull used as the source of the cells for the cloning process, or if they are more like those of a normal newborn calf."
Hill said it took 189 attempts - that is, transferring 189 cells into 189 different eggs - before a pregnancy ended in the delivery of Second Chance. Because Second Chance came from the oldest animal cloned to date, he has received intensive monitoring and treatment since birth by a team of veterinarians and intensive care technicians at the Texas A&M Large Animal Hospital. Like many previously cloned calves, at birth he displayed some symptoms that resembled those seen in premature human babies. However, Second Chance is now in good health, Hill said.
The successful cloning effort could dramatically impact the multi-billion dollar beef cattle industry in Texas and throughout the world.
"This could lead to new opportunities in cattle breeding, and for that matter, other animals," Hill believes.
Hill is a veterinarian trained in Australia and at Texas A&M who used the cloning work as part of his doctor of philosophy studies in physiology with Westhusin. He is also a member of another research team led by Westhusin that is involved in the Missyplicity Project, the first-ever attempt to clone a dog.
The Missyplicity Project is a 2-year effort to produce the first cloned dog. The anonymous sponsors of the project have invested $2.3 million to produce a clone of their pet dog, Missy, a mixed breed border collie. A team of about 20 researchers is working on the Missyplicity Project, and some of the knowledge gained by Second Chance is helping to advance that research.
The cloning of Second Chance was funded by the Texas Coordinating Board of Higher Education's Advanced Research Program and by Dr. Charles Looney of Ultimate Genetics in Franklin, Texas.
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