Cloned sheep show no ill health as they age
27 Jul 2016 by qmwwwtqmqt.d qmwwwtqmqt.d
New research has shown four clones derived from the cell line of Dolly the sheep have reached the age of nine and continue to be in good health.
New research has shown four clones derived from the cell line of Dolly the sheep have reached the age of nine and continue to be in good health.
Debbie, Denise, Diana and Daisy — the Finn-Dorset clones — were born in July 2007. Dolly, born in 1996, was the first animal to be cloned from an adult cell using somatic-cell nuclear transfer (SCNT). These animals, along with others that were born between 2006-08 were part of a study led by Professor Kevin Sinclair at the University of Nottingham.
Professor Sinclair said: “Despite technological advances in recent years’ efficiency of SCNT remains low but 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. 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.”
SCNT is a technique used in developmental biology in which a donor cell from a somatic (body) cell is implanted into an empty oocyte. The four Finn-Dorset clones are derived from the mammary gland cell line that led to the birth of Dolly. The other clones came from fetal fibroblasts.
Due to concerns raised about longevity and healthy ageing in SCNT clones — Dolly suffered from osteoarthritis — the sheep underwent a series of comprehensive assessments in 2015. They were tested for obesity, hypertension and osteoarthritis and this required the use of x-rays and MRI scans.”
Professor Sinclair said: “Healthy ageing of SCNT clones has never been properly investigated. There have been no detailed studies of their health. One of the concerns in the early days was that cloned offspring were ageing prematurely and Dolly was diagnosed with osteoarthritis at the age of around five, so clearly this was a relevant area to investigate.”
The study, led by Professor Sinclair, can be seen in Nature Communications.
