Chemeric-embryosThis is a further better approach by scientists from UK and Japan labs towards producing embryonic stem cells by reprogramming adult stem cells, published in Nature Methods.

Kosuke Yusa, Sanger Institute investigator and lead author on the study, claimed that the new research answers two questions: can we improve the efficiency of recovering cells with the original-state genome (typically, it is around one in 1000) and can we improve on the efficiency of the four factors?

Researchers further claimed that the new work adds one more factor to previous findings to double the efficiency of producing the new stem cells.

Moreover, the team added a selection step that enables efficient removal of the reprogramming factors from the stem cells after they have completed their task. Removing these factors ensures the genetic make up of these cells is an exact copy of the donor.

In this latest work, the research team used a trick of adding a gene that will kill the cell when a chemical is added to the growth solution. Only if the poison gene is removed along with the factors and the original cell genome restored, will cells survive the selection. If the poison gene is still there, they will die. This step improves the recovery of correctly modified induced pluripotent stem cells (iPSCs).

The second improvement was to add a fifth genetic factor to the cells, which improved the production of iPSCs twofold.

In the previous research, scientists successfully added genes for four genetic factors to reverse the loss of potency of human and mouse cells.
These factors reprogram the genetic machinery of the cell and, over several weeks, take the cell back to a more embryonic-like state.
Once reprogrammed, the genes can be removed, leaving the original genome of the cell undisturbed.

Presently scientists are looking forward to increase more effiency, they believed that combined with our robust selection step, they will able to much more rapidly develop and explore iPSCs  much more rapidly.