Researchers await cloning outcome
Students at Utah State University may soon be seeing double if present cloning projects remain on track.
Currently, students are cloning cattle and horses and have four fetuses of each animal, said Ken White, professor of reproductive biology.
The horse-cloning project is part of a partnership with the University of Idaho. USU students went to Moscow, Idaho one week a month over the summer to work with the horses, White said.
“We’ve produced pregnancies from each of our trips,” he said. “We’re keeping our fingers crossed that they continue to produce, because there is a high rate of loss with cloning.”
The oldest clone fetus, which was created in May, is close to 120 days old.
“Gestation is 340 days,” he said. “We still have a long way to go.”
White said horses are seasonal breeders. They have cycles in the spring and summer but don’t have cycles the rest of the year, so the research is done in the summer.
The partnership with Idaho has been going on since 1998, with Utah State providing the cloning know-how and Idaho supplying the horses and the knowledge of caring for them, White said.
The cow-cloning project is focusing on dairy cows, said Ben Sessions, a master’s student in animal science with a specialization in reproductive biology.
“Our big push now is that we’re trying to clone a dairy cow,” he said. “Dr. White makes the clones and we surgically put it into a donor cow and watch and hope she goes full term.
There are four cows currently pregnant with clones, Sessions said.
“We’re still keeping our fingers crossed that they stay pregnant. One is within a couple of months [of being born].”
Sessions’ project, which is being funded by the U.S. Department of Agriculture, is specifically researching the fertilization process.
“My area of research is trying to understand the process of fertilization better so we can mimic it better in-vitro in the lab so the clones that are created will have a better chance if survival,” he said.
White said it is important to understand how the sperm activates the egg because when clones are created, the egg must be activated by mimicking the natural process.
“Everything starts when that egg gets activated,” he said. “We identify the receptors involved in it and how it occurs.”
The cattle-clone embryos are grown in sheep for five to seven days; if they live, they are then transferred to cows, Sessions said. USU has performed between 15 and 20 surgeries in cattle to implant the clones.
Although four cows are currently pregnant with clones, White pointed out the fetuses often do not live to full-term. About one-half of pregnancies are lost in the first trimester. Of the ones that survive that, 25 percent are lost in the second trimester. And of those, 10 to 15 percent are lost in the third trimester, he said.
“It’s a project not for the faint-in-heart,” Sessions said. “We had one that was well into the second [trimester] that we lost. I carry rabbits’ feet, I don’t step on cracks and all kinds of other things. I try to be pretty cautious.”
White said he tells skeptics of his work cloning is basically making an identical twin, although he said he doesn’t receive
much opposition.
“We’re not doing any genetic manipulations of animals; we’re trying to amplify what nature’s naturally created,” he said. “I haven’t really experienced any opposition. I think people become much more concerned when you’re talking about human application.”
The research going on at USU can be used in many different applications, White said.
“There are a lot of implications with cloning, with agriculture,” he said. “Think of animals with high milk produce or weight gain in beef cattle, as well as animals that are valuable. You could theoretically take racehorses that had died and make copies of that.
“Another application is in endangered species,” he said. “You could take tissue samples and grow cells from that and regenerate animals.”
As far as humans are concerned, he said he doesn’t believe it’s necessary to use cloning for reproduction, but it could have other
applications
“I can see very important applications for therapeutic purposes,” he said.
He gave the example of someone needing a liver transplant. He said if the technology was available to take a skin biopsy and produce a liver that could be transplanted into a person, the recipient wouldn’t have to take rejection medicine because he would be 100 percent compatible with the organ.
“Ask yourself if that is an important application,” he said. “You can answer that for yourself. It’s not a door we want to close. It’s a door we want to monitor closely.”
So far, research shows clones are as healthy as their natural counterparts and their products are safe, White said.
“There have been a lot of studies looking at the production characteristics,” he said. “It has just barely been long enough to let that happen.”
There’s a 48- to 72-hour period where the animal is susceptible to things. Once they make it through that period, most will produce and develop normally.
“Milk from a cloned cow is identical to milk from another cow; all you’re doing is producing an identical twin,” he said. “The animals look normal.”
Sessions said his favorite part about cloning research is that it is new and current.
“I like how it’s the frontier of science,” he said. “There are a lot of benefits of cloning. We can have better cows and better beef from the cows. I like people’s reaction when I tell them that I’m working with cloning cows. I think a lot of people don’t know that we do that.”
-kcartwright@cc.usu.edu