Scientists announced Thursday that a new cloning technique appears to rewind the aging clock in cow cells, and they have produced six calves through the process that show signs of being younger than their actual chronological ages. What we have shown for the very first time is the cloning procedure is actually reversing the aging process. Researchers grew the fetal cells until they neared the end of their life span, then put those cells back into eggs, which they allowed to develop into calves. The study, published in the journal Science, measured a tiny part of the calves' chromosomes called telomeres. These are little caps on the ends of the chromosomes that carry the genetic blueprint inside cells.
Telomeres shorten as cells divide and grow older.
A cell dies once the telomeres are frayed beyond repair. The study authors found the telomeres in the cloned cows were much longer than those in normal cows of the same age, and in many cases they were longer than telomeres in newborn calves. What we showed in this paper is this clock gets reset. It remains to be determined whether this would extend the life of the animal. These findings are surprising because the first cloned mammal, Dolly the sheep, appears to be older than her chronological age.