https://vimeo.com/176456684/settings
Video: Prof Kevin Sinclair has been studying and caring for the sheep as they age
Four Nottinghamshire sheep which are exact copies of ‘Dolly’ are so healthy they have given new hope that cloning could help medicine and agriculture.
Dolly – the first-ever cloned animal – died at the age of six after suffering osteoarthritis, leading to early concerns that clones could age too quickly.
Debbie, Denise, Dianna and Daisy were produced from the same ewe as Dolly and are looked after by a team at the University of Nottingham led by Professor Kevin Sinclair.
They were produced using a process known as somatic-cell nuclear transfer, or SCNT.
Prof Sinclair and other experts have now completed the world’s first serious study on health and ageing in cloned animals.
The checked the sheep with MRI scans, heart tests and X-Rays as they aged between seven and nine – and all four sheep are in perfectly normal condition.
Picture: Debbie, Denise, Dianna and Daisy are now considered healthy
“Following our detailed assessments of glucose tolerance, insulin sensitivity, blood pressure and musculoskeletal investigations we found that our clones, considering their age, were at the time of our research healthy,” Prof Sinclair said.
Dolly caused a worldwide sensation in 1996 when she was successfully cloned and born at the Roslin Institute in Edinburgh. She died in 2003.
Her relatively early death meant questions were raised over the effectiveness of clones.
The process is still considered to be inefficient – with a significant number of attempts needed before the process successfully produces a healthy living animal.
But Prof Sinclair says the health of the other four sheep shows it can produce perfectly normal animals – the goal now is to work out why so many cloning attempts fail in the early stages.
“There are several groups across the world working on this problem at present and there is reason to be optimistic that there will be significant improvements in future,” said Professor Sinclair.
“These improvements will stem from a better understanding of the underlying biology related to the earliest stages of mammalian development.
“In turn this could lead to the realistic prospect of using SCNT to generate stem cells for therapeutic purposes in humans as well as generating transgenic animals that are healthy, fertile and productive. However, if these biotechnologies are going to be used in future we need to continue to test their safety.”
Prof Keith Campbell, who played a leading role in the creation of Dolly, joined the University of Nottingham in 1999.
He continued his work on reproductive biology until his death in 2012.
The four siblings of Dolly he oversaw were passed to other scientists at the university, who have continued to study them and care for them at its Sutton Bonington Campus.
