‘Dolly’ clones healthy and aging normally

Among 13 cloned sheep, four were “descended” directly from Dolly’s DNA and unlike their predecessor have been aging normally with none of the sicknesses that the first one endured. Image INQUIRER.net

Remember Dolly the cloned sheep? Well, it turns out that scientists made four more of her from her DNA and are now happily grazing and aging normally.

One of the chief concerns when Dolly was cloned 20 years ago was the premature aging that the clone experienced. The clone developed osteoarthritis at an early age and was eventually diagnosed with an incurable lung virus. This led veterinarians to decide to put her down and the UN to put a ban on human cloning in 2005. Several countries have also placed a ban on cloning of animals, The Verge reports.

However, a recent study suggests that other cloned animals may not succumb to the same fate as Dolly. Researchers from the University of Nottingham conducted health tests on 13 cloned sheep, four of which were derived directly from Dolly’s DNA strand, and found all of them healthy. Metabolism, heart function and blood pressure did not show signs of premature aging. While some suffered from slight arthritis in their joints, experts say it is no cause for concern.

Developmental biologist Kevin Sinclair, the lead author of the study, says, “They’re old ladies,” referring to the Dolly clones. “They’re very healthy for their age.”

The impact of this recent study on the overall outlook toward cloning is still unclear. There are still several health risks to consider, including birth defects. Once the clones reach the age of 10, they will be put down and researchers will proceed with a more in-depth postmortem study.