For more than 25 years, stem cells have been defined based on what they can become: more of themselves, as well as multiple different specialized cell types.
But as genetic techniques have become increasingly powerful, many scientists have sought a more molecular definition of stem cells, based on the genes they express.
Now, a team of Canadian scientists has identified 1,155 genes under the control of a gene called Oct4 considered to be the master regulator of the stem cell state. A comprehensive molecular definition of stem cells is emerging: according to this research, stem cells are cells that keep their DNA packaged in a flexible format, keep cell division tightly controlled, prevent signals that might trigger death, repair DNA very effectively, and reinforce all of these characteristics by tightly controlling how molecules can move within the nucleus. The study will be published in the June 20 edition of the online, open-access journal PLoS ONE.
"You could call this a theory-of-everything for stem cells," said senior author Dr. Michael Rudnicki, referring to the often-cited theory of everything for physics. Dr. Rudnicki is a Senior Scientist and Professor at the Ottawa Health Research Institute and the University of Ottawa. He also leads the Sprott Centre for Stem Cell Research in Ottawa and Canada's Stem Cell Network.