This article is from the WSSF 2010 AFRMA Rat & Mouse Tales news-magazine.
A strain of mice called the Murphy Roths Large (MRL) has regeneration properties never seen before in mice. When the ears had been punched for ID, these mice were able to close up the hole with DNA synthesis, cell proliferation, and regrew cartilage and hair. Further tests with tissue injuries showed these mice were able to regenerate with little to no scarring. Studies have shown that the basement membrane that blocks regeneration in most mammals disappears soon after the cell growth begins on these mice. Further studies have found two genes that may be involved in the regeneration ability and further mapping of the genes involved is underway.