In groundbreaking research scientists from China have for the first time created baby mice by using powerful stem cells from adult mouse skin.
Embryonic stem cells, taken from 'days-old' embryos, are able to develop into any cell type and, in mice, can be implanted into a mother's womb to create living mouse pups - they are the body's master cells, giving rise to all the tissues, organs and blood and are considered the most powerful kind of stem cells.
The research was carried out by two separate teams of scientists in China and the breakthrough was made using re-programmed adult stem cells which created 37 stem cell lines, and of these, three generated live births.
Australian Stem Cell experts say it is the first time "induced pluripotent stem cells" (IPS cells) have been used to make an entire mouse using mouse fibroblasts, which are cells found in connective tissue in the skin.
For the research the adult IPS stem cells were taken from the tail or skin of a mouse - the researchers introduced genes into the cells to reprogram them to become the equivalent of an embryonic stem cell.
The author of one of the studies which is published in Nature, Professor Fanyi Zeng from the Shanghai Stem Cell Institute, says her team produced 27 mice using IPS cells and the oldest mice are nine months old and while some are showing abnormalities, they are reproducing.
Professor Fanyi says this is the strictest test that can possibly be done to show that a cell is capable of forming every cell in the body and the research demonstrates how safe and stable these cell types are over the long term.
Professor Fanyi says the research offers hope for future therapeutic intervention using a patients' own re-programmed cells.
Dr. Andrew Laslett from the Human Embryonic Stem Cell Technology at the Australian Stem Cell Centre in Melbourne, who works with both IPS cells and embryonic stem cells, says the results have reinforced their work - he says though every new breakthrough in such adult stem cell technology inevitably evokes calls for work with human embryos to be abandoned, that action would be a mistake.
Dr. Laslett believes IPS cell technology still has a very long way to go for it to be considered safe and the only way to validate the IPS cells is to directly compare them to human embryonic technology.
In theory the research could mean that it is possible to clone someone using ordinary connective tissue cells found on the person's skin, but scientists say they are confident that their research will be used to understand the root causes of disease and lead to viable treatments and cures of human afflictions.
The research papers are published in the journals Nature and Cell Stem Cell.