The early mouse embryo contains a transient population of pluripotential stem cells which
are responsible for generating both the foetal primordia and extraembryonic membranes.
The characterisation of murine embryo stem cells and their isolation and propagation in
culture provides the first instance in which pure populations of normal stem cells are directly
accessible to the researcher. This marks a considerable advance in stem cell biology which
may pave the way to the dissection of general stem cell control mechanisms and the …