6 Cloned Cows Show No Signs of Early Aging

Massachusetts scientists say they have cloned six cows that show none of the worrisome premature aging reported in Dolly the sheep. In fact, the cows’ cells seem to have a surprisingly prolonged youth, the scientists report.

The finding is important because it could erase doubts about trying to use cloned cells to fight diseases, doubts raised when scientists discovered Dolly’s cells appeared older than she was.

The cloned cows--the oldest turned a year old this week, while the others are 7 months old--have cells that appear as young as the cells of newborn calves, researchers with the biotechnology company Advanced Cell Technologies report in today’s edition of the journal Science.

Unlike Dolly, the cows were cloned from cells nearing the end of their life span. If even very old cells can have their “aging clock” essentially rewound, then scientists might one day be able to clone customized replacement tissues for patients suffering from diabetes, Parkinson’s or other diseases, say experts on cellular aging.

“It’s important not to over-dramatize this as a ‘fountain of youth’ thing,” said one of the nation’s leading experts on cellular aging, Jerry Shay of the University of Texas Southwestern Medical Center.

Instead, Shay said, the study provides “the first very dramatic proof” that people’s very old cells could one day be rejuvenated for tissue engineering.