Until now, stem cells have been obtained from mice, primates and humans, but never from amphibians. But, because the African clawed frog is easier to study than mice and humans, the Edinburgh team anticipate that it will become an important research tool in their quest to understand and, ultimately, treat disease using stem cells. The results of their study are published in the current edition of the journal Development.
The key protein in humans, called Oct4, which governs the process of unlimited division of stem cells, has an equivalent in the African clawed frog, called PouV. This new research shows that the two proteins are not only similar, but perform the same function both bind to DNA and activate certain genes that keep stem cells dividing. Indeed, embryonic stem cells lacking the Oct4 protein stop dividing and become specialised.
In the study, Dr Gillian Morrison introduced frog PouV proteins into mouse embryonic stem cells lacking Oct4 and found that the frog proteins "rescued" the stem cells in other words, the cells recovered their ability to divide without limit. Dr Morrison obtained similar effects when she introduced PouV proteins from another amphibian, the axolotl (a type of salamander).
To find out exactly what function PouV proteins perform in frog embryos, Dr Morrison injected special compounds into very young
Contact: Ana Coutinho
University of Edinburgh