Using a technique called somatic cell nuclear transfer (SNCT), the team headed by Dr Teruhiko Wakayama were able to produce 581 clones of one original 'donor' mouse, achieved through 25 consecutive rounds of cloning.
SNCT is a famous technique of cloning in which the cell nucleus which has the genetic information of the individual to be cloned is inserted into a living egg with the nucleus removed. This method is found to work very well both in laboratory animals as well as farm animals.
Scientists from Japan were able to surmount some of the limitations of SNCT which had caused low success rates and restricted the number of times mammals could be recloned.
To overcome this, Wakayama and his team added trichostatin, a histone deacetylase inhibitor, to the cell culture medium. They were able to improve the efficiency of cloning up to 6 fold using this technique. They were able to clone the mice repeatedly about 25 times successfully.
The 581 mice were healthy, fertile , and gave birth to healthy pups that lived a normal lifespan of about two years, similar to the ones born normally.
"This technique could be very useful for the large-scale production of superior-quality animals, for farming or conservation purposes," Wakayama added.