THE discovery two years ago of a technique for creating an immortal line of
human embryonic stem cells (ESCs) raised hopes that it would one day be possible
to grow endless supplies of specialised cells, or even organs for transplants.
But researchers are still puzzling over the exact biochemical signals needed to
control stem cells.
A key step on that road has now been taken with a study of mouse ESCs, which
shows that different levels of a “gatekeeper” protein called Oct-3/4 steer the
cells towards becoming placenta, body tissues or another generation of ESCs.
“The Oct-3/4 work tells us we are going to figure all…
