X-Message-Number: 13652 Date: Thu, 27 Apr 2000 17:37:00 -0400 From: Jan Coetzee <> Subject: Cloning Produces Unnaturally Young Cattle Report: Cloning Produces Unnaturally Young Cattle By Maggie Fox, Health and Science Correspondent WASHINGTON (Reuters) - Scientists who cloned six cows said on Thursday the animals show signs of being even younger than their chronological ages, and said this could mean cloning technology offers a true fountain of youth. The cloning process seemed to have literally turned back the aging clock in the cells of the six heifers. The researchers said it might be possible to use cloning to create organs that are nearly immortal for use in transplants, or tissue lines to treat diseases of aging such as Alzheimer's, arthritis and heart disease. ``Not only were we able to clone calves ... but these animals appear to have cells younger than their chronological age,'' Robert Lanza of Advanced Cell Technology, Inc., who led the study, said in a telephone interview. Clock Gets Reset ``What we showed in this paper is this clock gets reset. It gets wound back up,'' said Dr. Michael West, president and chief executive officer of the Worcester, Massachusetts-based company. ``It remains to be determined whether this would extend the life of the animal.'' The findings, published in the journal Science, are surprising because the most famous cloned animal, Dolly the sheep, appears to be older than her chronological age. Dolly, whose birth was announced in 1997, was the first mammal to be cloned using an adult cell. Her makers at the Roslin Institute in Edinburgh, whose technology now belongs to Geron Bio-Med, found signs that her cells, when she was born, were the same age as the cells of the 6-year-old ewe from which she was cloned. They calculate this by looking at the telomeres, which are little caps on the ends of the chromosomes that carry the genetic blueprint inside cells. Each time a cell divides, the telomeres become a little worn. When they are frayed beyond repair, the cell dies. This stage is known as senescence. Dolly had old telomeres. But the six heifers, cloned from cells taken from a 45-day-old fetus, have exceptionally young telomeres. What is even more surprising is that the cells that Lanza's team cloned were not fresh and new. They had been grown and allowed to divide over and over again in the laboratory until they were senescent. The team, which included researchers at the Lakenau Institute in Wynnewood, Pa., and Thomas Jefferson University in Philadelphia, fused the cells into cow eggs using a slightly different cloning process than that used to make Dolly. ``The egg cells acts like a little time machine and can take it back, as far as we can tell, to the beginning of life,'' West said. ``Totally Cool'' ``It's kind of abracadabra and through processes we don't understand, they get reverted. It's totally cool.'' The medical implications are profound, West said. ``It's the first day in a new era in treating age-related disease,'' West said. ``We could take one young cell from a patient and make hundreds or thousands of young cells and put them back in the patient and give them back a young immune system or give them back young cartilage in their knees,'' he added. ``If you had a damaged heart, we could take a few cells from you and grow up new heart cells and these would be your own cells so you wouldn't reject them,'' added Lanza. Of course, this would involve technically cloning the patient -- something called therapeutic cloning -- and there would be opposition to allowing it. But Lanza said the cells created would never be slated for development as a human embryo. ``Once people understand the science here, the more they hear about it, the more likely they are going to say this is a good thing,'' he said. His team is continuing to work with cloned cells. In 1998 they created clones using human cell nuclei and cow cells, which did not develop into embryos but into a dishful of cells. Lanza said his team does not quite understand how the heifers became ``younger''. But he said genes whose activity usually dies down as a cell ages were especially active. ``These results suggest the animals are younger than their biological age,'' Lanza said. ``When other cows the same age start to grow old and frail, their cells should be able to divide the same as a newborn calf's. They should be able to repair damage due to disease and aging and should live longer, healthier lives. Only time will tell. Cows allowed to lead natural lives live to be 24 and older. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=13652